The great big block 4th gen swap info thread
#1
The great big block 4th gen swap info thread
So this has been discussed some here and there but I haven't been able to find any good resources on this swap. I have been getting a lot of calls on this lately as well, so I figured I would post up my experience and info that may be useful to others looking to do this swap.
First off, I'll cover the mounting. Yes, there is a bolt in option. You do not have to run a motor plate. Our KM005 or KM015 will bolt in to your 93-02 car and bolt to any traditional BBC, and even the hybrid elephant 8.1.
The KM005/KM015 has a free standing motor mount design that bolts directly to the block and hugs tightly to the engine to maintain header clearance. They us a polyurethane disc mounting to isolate vibration for street use, or a solid billet aluminum mount upgrade is available as well. Or, if you do decide to get crazy later and run a motor plate setup, the stands can be unbolted and removed. You also have the option to buy LS motor mount stands from us and swap to an LS without changing k members.
For my personal car, I opted for our KM015 turbo style k-member just to get as much room as possible for future activities. I also removed the A/c and installed a block off plate. I then also opted for a manual brake kit. This was due to running a tall valve cover to clear my rockers. This will pretty well be require for a tall deck block motor. So with these things in place, I had a pretty good amount of room to work with
Even with the stock steering rack still in place, I had ample clearance between it and my average sized aftermarket oil pan. This should be the same for a stock pan, or have even more clearance most aftermarket fabricated style rear sump pans
If you plan on running a carb, YOU WILL HAVE TO CUT YOUR COWL! There is now way around it. You can get away with just trimming the center to clear your carb, but if you are like me and have made the decision the car will see little to no street time, then you can take it all off for clearance.
I will add more to this tomorrow when I get back in. Out of time for today!
First off, I'll cover the mounting. Yes, there is a bolt in option. You do not have to run a motor plate. Our KM005 or KM015 will bolt in to your 93-02 car and bolt to any traditional BBC, and even the hybrid elephant 8.1.
The KM005/KM015 has a free standing motor mount design that bolts directly to the block and hugs tightly to the engine to maintain header clearance. They us a polyurethane disc mounting to isolate vibration for street use, or a solid billet aluminum mount upgrade is available as well. Or, if you do decide to get crazy later and run a motor plate setup, the stands can be unbolted and removed. You also have the option to buy LS motor mount stands from us and swap to an LS without changing k members.
For my personal car, I opted for our KM015 turbo style k-member just to get as much room as possible for future activities. I also removed the A/c and installed a block off plate. I then also opted for a manual brake kit. This was due to running a tall valve cover to clear my rockers. This will pretty well be require for a tall deck block motor. So with these things in place, I had a pretty good amount of room to work with
Even with the stock steering rack still in place, I had ample clearance between it and my average sized aftermarket oil pan. This should be the same for a stock pan, or have even more clearance most aftermarket fabricated style rear sump pans
If you plan on running a carb, YOU WILL HAVE TO CUT YOUR COWL! There is now way around it. You can get away with just trimming the center to clear your carb, but if you are like me and have made the decision the car will see little to no street time, then you can take it all off for clearance.
I will add more to this tomorrow when I get back in. Out of time for today!
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
#3
Ok, to pick up where I left off.
The next big step, and probably what I get asked about the most. Headers. If you run a big bore space block or a non conventional head (big chief etc), your only option will be Lemons. They make custom fab headers for this swap. They aren't cheap, but neither is anything relating to big motors of this caliber once you go that route. If you are like me and are running a standard deck height and conventional head I have good news for you and your wallet. Off the shelf 64-72 chevelle headers will work. I have a set of Hooker Super Comp (P/N 2455) and they work great with minimal modification.
The driver's side will go right in without touching a thing.
Then it was time for the passenger side. This side will go almost all the way on without touching, but it held up by about 1/2" by the rear primary tube contacting the firewall just below the a/c box opening
So I just slightly dented the outward bend on the tube and pushed the firewall back some in this area. It takes a little work since it is on an outwards bend. But, you don't have to go far
(Ignore the wire, it has been moved)
and once it's all said and done
Ignition. You will need a low profile distributor. You cannot run an HEI. It will not fit without doing a full firewall removal/custom windshield. Even my Mallory Comp 9000 is tight. Also, if you decide you need to pull the distributor for any reason, the motor will have to come out. You physically cannot remove the distributor with the engine in place under the stock windshield. So keep this in mind when setting everything up.
Now the hard part is all done! All you have left is wiring and fuel which are very simple and have many variables for your combo. I also get 2 other questions about this that I feel I should cover here as well, as I'm sure anyone looking at this swap will be wondering
Yes, all 8 plugs are easily accessible. I can do a plug change in about 10 mins. Which is essential being mine is a nitrous combo.
Yes, the valve covers are easily removeable. So those with solid lifter cams will not have issues pulling them to adjust lash.
No, you cannot run a stock hood. You will need a cowl hood of some sort. Even open carb is pretty tall, so if you plan to run any sort of air cleaners, you will need room. If you run a front facing EFI intake (pro flow, vortec intake) you may be able to get away with it. But... why?
To give some ideas of carb and valve cover height in relation to the cowl/ fenders:
Yes my radiator is just sitting there in these pics. Don't judge me lol
If you have any other questions on what is needed for the swap feel free to message me or give me a call here at the office and I can discuss it with you and give some pointers. We have all of the parts to make this swap as easy as I have shown
The next big step, and probably what I get asked about the most. Headers. If you run a big bore space block or a non conventional head (big chief etc), your only option will be Lemons. They make custom fab headers for this swap. They aren't cheap, but neither is anything relating to big motors of this caliber once you go that route. If you are like me and are running a standard deck height and conventional head I have good news for you and your wallet. Off the shelf 64-72 chevelle headers will work. I have a set of Hooker Super Comp (P/N 2455) and they work great with minimal modification.
The driver's side will go right in without touching a thing.
Then it was time for the passenger side. This side will go almost all the way on without touching, but it held up by about 1/2" by the rear primary tube contacting the firewall just below the a/c box opening
So I just slightly dented the outward bend on the tube and pushed the firewall back some in this area. It takes a little work since it is on an outwards bend. But, you don't have to go far
(Ignore the wire, it has been moved)
and once it's all said and done
Ignition. You will need a low profile distributor. You cannot run an HEI. It will not fit without doing a full firewall removal/custom windshield. Even my Mallory Comp 9000 is tight. Also, if you decide you need to pull the distributor for any reason, the motor will have to come out. You physically cannot remove the distributor with the engine in place under the stock windshield. So keep this in mind when setting everything up.
Now the hard part is all done! All you have left is wiring and fuel which are very simple and have many variables for your combo. I also get 2 other questions about this that I feel I should cover here as well, as I'm sure anyone looking at this swap will be wondering
Yes, all 8 plugs are easily accessible. I can do a plug change in about 10 mins. Which is essential being mine is a nitrous combo.
Yes, the valve covers are easily removeable. So those with solid lifter cams will not have issues pulling them to adjust lash.
No, you cannot run a stock hood. You will need a cowl hood of some sort. Even open carb is pretty tall, so if you plan to run any sort of air cleaners, you will need room. If you run a front facing EFI intake (pro flow, vortec intake) you may be able to get away with it. But... why?
To give some ideas of carb and valve cover height in relation to the cowl/ fenders:
Yes my radiator is just sitting there in these pics. Don't judge me lol
If you have any other questions on what is needed for the swap feel free to message me or give me a call here at the office and I can discuss it with you and give some pointers. We have all of the parts to make this swap as easy as I have shown
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
#4
Nice swap. Did mine with the #KM005-1 k-member and the RK001 manuel steering. Used the same headers with the same mods. When i did my LS swap from the BBC i just used some dirty dingo swap plates on the same mounts. BMR didnt offer a swap mount at the time.
#6
Very nice. Did you do an offset plate or did you use the adjustable ones? I went the opposite way. This car's previous incarnation had a Turbo LS2. I decided that was "too mainstream" and I wanted instant torque, and a friend gave me a killer deal on this big block combo. So I decided to try it and see how far I could push this thing. The only thing I am disappointed with so far is the obvious added nose weight. I did some additional weight reduction to help offset it some, and removed the front ballast. The car had problems with wanting to go up on the bumper before, so this along with the new coil-overs and geometry changes should hopefully keep it more under control
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
#7
Also here are some updated picture of everything finished with the radiator actually mounted, as well as the fuel system finished. This shot give a good height relation as well. A cowl hood is needed for this swap
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Trending Topics
#9
Very nice. Did you do an offset plate or did you use the adjustable ones? I went the opposite way. This car's previous incarnation had a Turbo LS2. I decided that was "too mainstream" and I wanted instant torque, and a friend gave me a killer deal on this big block combo. So I decided to try it and see how far I could push this thing. The only thing I am disappointed with so far is the obvious added nose weight. I did some additional weight reduction to help offset it some, and removed the front ballast. The car had problems with wanting to go up on the bumper before, so this along with the new coil-overs and geometry changes should hopefully keep it more under control
#10
#12
Might try to take it out for some test n tune this weekend to shake it down on motor. Then we'll start playing with the kit. It ventured out of the shop last weekend. Found a couple small bugs that were easy fixes. It sounds quite healthy though
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
#13
any more details on the motor combo? do you have a hp or et goal? following the thread looks like a fun project
#14
This is just a basic setup to get it up and going and have some fun in street car classes with for now. 454, L88 closed chamber heads with some work, 2.25 intake, 1.88 exhaust valves, Comp double springs, .710 solid roller cam, Crane Gold 1.7 rockers, Single plane Victor intake, 1050 Dominator. Got a plate kit on it too, so I'll see what it will do with that. Hopefully I can put the car back in the 8's. It was running 8.90s with a SBE ls2 turbo combo with a much less efficient chassis setup. This setup should be around the same weight and make the same power but with more torque. This will hold me over until it's time for a real motor. Here's an updated engine bay shot. Windshield is getting installed tomorrow. Kept a stock glass windshield to fit into a couple local no prep and "street car shootout" classes.
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
#16
This car went 8.90 at 820whp at 3000lbs and 1.29 60'. Weight should be close to the same. This motor made ~550 NA and I'm hitting it with an .082 jet so I should be around the same power. This suspension and chassis setup is a good bit more efficient than the last also. This motor went 10.70's consistently naturally aspirated in a full weight stock suspension 67 Chevelle. Big motors make big power without a lot of effort
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
#17
This car went 8.90 at 820whp at 3000lbs and 1.29 60'. Weight should be close to the same. This motor made ~550 NA and I'm hitting it with an .082 jet so I should be around the same power. This suspension and chassis setup is a good bit more efficient than the last also. This motor went 10.70's consistently naturally aspirated in a full weight stock suspension 67 Chevelle. Big motors make big power without a lot of effort
#18
This car went 8.90 at 820whp at 3000lbs and 1.29 60'. Weight should be close to the same. This motor made ~550 NA and I'm hitting it with an .082 jet so I should be around the same power. This suspension and chassis setup is a good bit more efficient than the last also. This motor went 10.70's consistently naturally aspirated in a full weight stock suspension 67 Chevelle. Big motors make big power without a lot of effort
#20
Car is running, just been in need of final tuning. Changed a few last minute things around. I keep looking at stuff and not being satisfied with it and changing it up. They also closed my local track so now the closest one is almost 2 hours away. Trying to have it out to an event here next month.
__________________
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!