Thanks!

I can't say for sure, but I doubt if any of the good headers will fit on the 3rd gen F-car. If you look at those lower A-arm rear pivot points, you'll see they eat up a LOT of space in that area. I even thought about trying to swap a 4th gen front subframe in to solve the problem; but the more I looked, the more I thought that should be a project for another day!!

 

So, what are you going to do with those MACs?

 

I don't know yet. I have a lot of time and effort in them. First I cut off and welded up all of the emissions fittings, then I spent a bunch of time smoothing the ports to remove the huge weld beads that MAC leaves in there, and then sent them off to Jet Hot for their coating. They are a beautiful sight now!! I have them bolted to another LS1 in the shop. I may just keep them for display.

Sorry to hear about the overheating problem!! Not good at all!

 

Hey John, Sorry to hear about the headers. I was really hoping that the macs fit so I could order some for myself. I used the hooker shorties. They fit fine except where I needed to clearance the driver side where there was interference with the steering knuckle.
Anyway, I was curious to see where you were in the project and when you thought you'd get to the track. I don't have anything to compare to around here. I'm curious about what fuel pump you ended up with and lots of other things. Good luck, and keep us posted. Sean

 

The car is now on the road! I finally got the exhaust stuff together and installed the other day, and it really sounds and runs nice. I had driven it up the road a couple of times with open manifolds, but that was just too load to enjoy or evaluate anything. I then jury-rigged a couple of cats onto the car so I could drive it at a sane sound level and that helped. But now the exhaust is finished using using a MAC offroad Y pipe assembly (modified for the 3rd gen body AND for the 2001 cast iron manifolds), Flowtech 3" cutout, with 3" intermediate pipe, and the STOCK TPI muffler. This would not be loud enough for a lot of guys, but the thing really has a nice sound both at idle and while driving. The idle sound reminds me alot of the '69 302 Z28 I had many years ago. At the track I will open the cutout anyway, so I am very pleased with the exhaust system.

I am using the stock TPI fuel pump at the moment. It seems fine, but more testing is needed. I have taken some WOT data with the Tech 2, but I was running open loop at the time, so I can't look at any O2 voltages. There was no knock retard though, with 6500 rpm full throttle upshifts. Now that the O2's are in place, I'll record a couple more runs and see what the voltages look like.

I've got some Hoosier QTP tires ordered, and as soon as I get them in and on, I think it's track time! I also got some 3.73 gears, but I'll run it first with the 3.23's and see how it does. I bought some control arms with relocation brackets, and a new torque arm too, but I don't need all of that to start out with.

Here are a few of the install pics. I'll have a BUNCH of pics up on the website real soon now.

<img src="http://www.speartech.com/91Z28TPIout3_a.jpg" alt=" - " /> <img src="http://www.speartech.com/91Z28LS1_engine_finished1_a.jpg" alt=" - " />

<img src="http://www.speartech.com/91Z28LS1_engine_finished2_a.jpg" alt=" - " /> <img src="http://www.speartech.com/91Z28LS1_in-car1_a.jpg" alt=" - " />

 

Excellent install <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" /> . It looks better than the clean stock engine in my brother's '86 IROC. He is planning to get another daily driver late this year and then start messing with the old 'ROC. He wants an engine kit with a carb <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> , I am trying to sway him to an LS1.

 

John please update this when U get a chance thanx and good luck ! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

Thanks for all the info your providing, I have a 91 RS, I'd like to swap an LS1 into when the 305 TBI dies. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

I'm doing the same. I installed a '99 SS LS1 engine into my '89 IROC Convertible. It had the 4L60E. I purchased a Street and Perf wiring harness which is pretty good. The problem is that when I spoke with the Smog Police here in San Diego I was told that the new OBDII smog standards require using all original smog equipment from the '99 car. That means using the gas tank because of the evap circuit and vacume canister are located on the gas tank.

Any advice on this would be helpful. Thanks!
Bruce <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

 

Great info and great swap!!

I would look at changing out the pump...I think your stock pump is going to have problems keeping up.
What is the curb weight of the car? Is it lighter than a fourth gen?
What cam specs did you go with? A little more exhaust duration will help with the stock 2001 manifolds.

Do you think you could have done the swap with a six speed?

What catback exhaust are you running?

Cheers,
Chris

 

Finally! I've got the pics together and the car back from the body shop. It needed a LF fender and various nicks and chips taken care of. Here's the link to the project build up. Any comments positive or negative are welcome.

http://www.speartech.com/coproj-1991ls1.html

Let me know what you think. I'm ready to take it to the track as soon as time permits. The rear end may be the weak link, due to high mileage. I have a set of 3.73 gears to put in it, but for now I will go with the stock 3.23's and see how it does. I am modifying the stock TPI air cleaner assembly to get as much cold air in as possible. I hope it doesn't turn out to be a restriction because I like the look of it. It's gives it a nice factory look. Time will tell.

 

Chris ARE 360:

Yes, the pump will probably be changed for reliability. I was surprised that it was able to keep up with this thing. It's being taxed harder than it ever was feeding a 350 TPI!
I don't know the weight, but I will get it weighed. I wouldn't be surprised if it was a little lighter than a 4th Gen, but I don't have any numbers to go by. Just looking at No ABS, just one airbag, less stuff in general.

The cam is a Comp .566, 222@.050 straight across with a 114 LSA.

I could have done it with a 6 speed. I have a sweet 2000 6 speed complete package in the shop with 17,000 miles on it. But one of my big goals with this car is drag racing, and I'm much more comfy pounding an auto with a converter, as opposed to hammering a manual trans. Just a preference of mine.

I'm running a MAC off road Y pipe into a 3" and then out thru the stock TPI muffler. Although not loud, it sounds VERY aggressive. It reminds me of my OLD 69 Z28 with solid lifter 302 engine. Just a good, healthy sound. At the track, I'll uncap a Flow Tech cutout.

Check out the link above for the complete run down.

 

Congrat's John on a very nice & clean swap! Your documentation is very nice also, brief, to the point and succienct.

I'd just like to make sure that people know how well your reworked wire harnesses work too! I can't count the number of e-mails that I have received over the months from people who have selected big name swap harness makers and only found out that they are a piece of garbage. You do awesome work John!

 

That thing looks great, excellent job! I'm really curious to see how she runs so I have something to compare to. I'm not exactly happy with my time of 12.35 @ 111.89, but I did't get enough runs to dial it in and figure out how best to launch the thing. I kind of had the rear end and tranny in mind when I ran it. You surely have a better cam and converter. I chose the hotcam(because I'm broke) 4:10 gears, 3000 vig,Ls-6 intake, asp pulley,hooker shorties etc. I also had a guy clean the heads up some, although I'm not sure how much this helped or hurt for that matter. I didn't weigh the car with the L98 in it, but with subframes, baybrace, stock wheels and tires, and ~75 lbs of dynomat, the car weighed 3250. Again, great job, and good luck at the track. Sean

 

yo John,

If i send you a LT1 harness from a roadmaster what would it run me to rework it for a old style pickup (72), also do you wire around VATS?

Jeremy

 

And by the way John, just slap together your own headers for this car...I did <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Personally I felt doing the swap required more skills than building the headers anyway so you're there <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

John,

Great job on the headers! I don't know if you should put them on the car or frame them and hang them on the wall!! I may have to do something like that eventually.

 

LS1IROC: Thanks! Our setups are similar. I have no idea how my car will run, but I wouldn't be too disappointed with a 12.35 timeslip! That's pretty quick, especially if there are some issues that need to be dialed in.

 

ISERCASTiK: sent you an email.