430 hp 70

iTrader: (3)

Posted this over at PT.com, but ill give it a shot here also.


im in the process of building a PT 70 chevelle and looking at a GMPP lsx block. original plan was for a gen 1 dart block based 434, but ive seen the light with the gen 3 and 4 stuff. ive tried searching, but i have too many questions and im not getting anywhere. if i can just get a start with these, it will help relieve the overload.

is it necessary to cut the crossmember when using a tko 600 and only ps and the alt (no ac)? i dont think i will have the same issues on the front of the motor since im not using ac, but im not sure. frames been based and cleared, so id rather not have to cut. who makes the best mounts for this application?

im looking at over a 4" stroke, so who makes a pan that will accept this? anything stock that will fit?

since im waaaaay new to the efi stuff, who makes a good computer for a ~650 hp na motor? what is needed for electronics (coil per cyl, ???)

how much more $$$$'s are involved to go with efi vs a carb (different manifold, rails, computer etc.) plus what is my etc?

what judges whether its cable or tps? can it be either?

do all the sensors have to be hooked up for a carb application? what can be left off a non smogged efi?

i can build a bad *** gen 1 434 for right around 9k. just not sure i really want the extra headache and the extra money for a like powered gen 4.

thanks, Tim

'JustDreamin'

I'll Take a stab at some of these.
Can't help you there, not familiar with the A-body.
Stock blocks can go to 4" without clearancing. And with the deep skirt block, most oilpans do just fine. F-body pan is fairly tight at 4", but it'll really depend upon your exact stroke / crank, and what rods you're running. The factory windage trays will probably need to be shimmed down.
Really depends upon what you want. The factor PCM is capable of controlling that hp level without difficulty. If you want to go carb'd, you've got the option of running the coil per cylinder and an MSD box (as a package) or running a special front cover and distributor (this is probably more expensive than the MSD setup, unless you don't already have the coils).

Depending upon a whole bunch of variables, EFI vs Carb could go either way. I'd bet that you won't hit your number without a FAST intake or something along that lines, so that will add to cost.

You can run either cable or DBW (drive by wire). Really depends upon your setup. I'm sure picking one or other will limit which PCM's you can use (if you're going EFI) but there are ones available to go either direction.

No, all the sensors are not necessary for carb applications. A Carb / Dist application doesn't really need any sensors. A Carb / MSD setup will require some sensors (like TPS and such). A non smog EFI setup will not require all of the sensors / connections (like the purge solenoid, or rear O2's) but will require most of them.

I can't tell you what your money will buy in the LSx family. But I can tell you, they're pretty stout motors, with alot of potential (like the L92 heads that are capable of 300cfm stock). I'd suggest you do a little shopping. There are plenty of vendors on here that can sell you anything from mild to wild.

'JustDreamin'

Shawn @ VA Speed

iTrader: (3)

you should have to cut the crossmember if not using the ac,however the f body oil pan will not fit.canton makes a nice conversion oil pan for these,you do have to relocate the oil filter when using that pan.
I can tell you this,its going to cost way more to build and put in a nice lsx motor than the old gen 1 small block,but you would end up with a lot nicer piece in the end.

stealth71

iTrader: (15)

Search around on here there are quite a few A-Body swaps in various stages of completion. The easiest way to start a LSx swap is to buy a pullout that is complete with harness, PCM and accessories. A F-Body is a good start. I got my engine to fit without modifying the stock F-body pan. You could part out the pieces of the LS1 that you don't need or want. If your planning on building a pretty much new motor then you could sell the long block, minus covers (timing chain, valley, rear cover, oil pan.) I would stick with EFI, going carb doesn't really save any money and there is tons of info on the net about tuning these things. There are a couple options for intakes: 1) stick w/ the stock LS6 intake (assuming 01+ LS1) 2) get a GMPP or Vic Jr. and run a 4150 style TB on top. The Single plane intakes make a lot of power on these motors.

If you are not running AC you shouldn't have to cut anything on the crossmember. I don' t have any TKO600 knowledge, but I assume it will just require some trans crossmember mods and possible some trans tunnel work. I am using the BRP style motor mount adapter plates and moved the frame side mount then redrilled.

Stick with the factory PCM. They work great to over 1000hp.

Drive by wire vs. Cable: If you stick w/ the LS6 style intake you could go DBW, but it isn't necessary. If you go single plane I think a cable pull throttle is the only option. Lokars throttle cable is an easy install and fits the stock Chevelle pedal.

Not sure about the carb sensor thing, but probably need to keep the important stuff for the ignition. Crank position, cam position. Not really sure. I kept EFI on mine and ditched the AIR, rear O2's, EVAP, A/C and cruise control.

The biggest difference in Gen I vs. LSx is weight if you go with an aluminum block. The EFI can also help make a very well mannered street car out of a beast.

Are we talking 650hp motor or wheel?

You should be able to get a complete engine for about $2500. Built forged short block is about $4500 + heads, cam, upgrades ~$4000.

Check out the link in my sig for my build pics and info. I'm sure the other A-Body guys will chime in.

stealth71

iTrader: (15)

F-body pan will fit. I am running one with no mods.

Shawn @ VA Speed

iTrader: (3)

My Bad.

430 hp 70

iTrader: (3)

thanks for all the help so far. the tko 600 wont be a problem as far as i know. i do need to cut the tunnel, but unless the lsx motor is in a much different spot, there shouldnt be much difference. ive read about the motor being an inch back on some conversions. but what about height?

the plan is to use the lsx iron block with a 4.125 bore and 4" stroke (id like to get more ci, but i have to see what will work first). i dont want to go near the max bore, but with .125 left, i could go more here. im not sure what the best stroke is for this block. ive read that itll take 4.25, but with short bores, i dont want to put that extra stress on the piston with a high pin location. plus, if im going to run into pan and crossmember issues, a 4" stroke may have to do.

it will also be topped with a set of afr heads (again best on gen I, but maybe not here?). other than that, i dont know which direction ill be going. i guess at this time, ill plan on the carb and msd option since that seems the easiest. once i get more info, i may lean back towards the efi.

what sort of pulley kits are out there? everything i have found so far uses a serpentine setup. has anybody made their own brackets and used a v belt setup? is their a clearance issue with the water pump? it just seems much cleaner than what i have seen so far.

so far for a carb setup im looking at an extra

650 extra for coils (msd or something else????)
200+ extra for headers
250+ extra for rotating assembly
350+ extra for heads
blocks are a wash
plug wires are a wash
manifolds are a wash
msd boxes are a wash
carbs are a wash


where are the extra costs? i could justify it for the extra $1500, but i know theres got to be more. what about oil pumps, water pumps, bolts, bearings, timing chains, sensors......

thanks, tim

430 hp 70

iTrader: (3)

well ive done some more searching and i hope i made some progress. Has anyone used the autokraft stuff? their pan looks real good and uses the stock filter location, but im not sure if it will fit a chevelle. 400 bucks and no core charge just about beats everyone. anyone used their mounts? how do they compare to the ats sandp etc...

thanks, Tim

stealth71

iTrader: (15)

Why not stick w/ a stock F-body or CTS-V pan? Why not use the stock serpentine setup? Stock coils are fine and MSD... make no improvements. I had to go with MSD wires for header clearance. Seems like your over complicating things and adding unneeded cost.

Have you read anything on the new LS3? Those heads are supposed to flow really well, and would probably work on 4.125-inch with a little work, since the LS3 is 4.06-inch.

Are you dead set on going carb? Can you fab any parts/adapter plates?

430 hp 70

iTrader: (3)

im not dead set on anything right now. from what i have read, i have to modify the stock f body pan to get it to fit. since the cost of a pan with mods is almost 400 and some still dont fit, the new pan seems like a good option.

i can fab just about anything. but for 40 bucks why spend the time if something else is known to fit. i cant justify saving 30 bucks when it takes me that time alone to make it to and back from the metal yard.

thanks for the info on the coils. it seems like a lot of guys are using the factory stuff and either the aftermarket hasnt stepped up or the gm stuff is just that good.

good info on the ls3, ill give those heads a look

thanks, tim

forcd ind

iTrader: (7)

i was pretty much in the same boat-i have a 69 i am putting a procharged 6.0 motor in-after 40 years of s/b, b/b, i felt like a ford owner looking for parts
i like to fabricate, but with the body work, paint and everything else, i was looking for some short cuts
i used the hooker headers, their engine adapter mounts, and a caddy cts oil pan($150) it all fit up great, minor lock to lock interference w/tie rod ends, but i'll take care of that-i mocked it up with a turbo 400 trans first
a tko600 should only need the tunnel mods (i did one in a 70)
i am running a vette acces dr (to clear steering box) with 8 rib setup for the procharger
i am going to start out with a carb intake, msd ign-quicker, easier for me, then make the switch to f/i down the road-is prob over $2k to use f/i, with intake, wiring, ecu, injectors, etc
i am using the cast iron 6.0 block, stock polished crank, aftermarket rods, wiseco pistons, and the stock 317 truck heads and zo6 cam-i figure the procharger will give me the power i need on top end, but i should have a decent idle and low speed driveability-i am setting the turbo 400 up with a switch pitch converter(dual stall) poor mans overdrive-lol

430 hp 70

iTrader: (3)

forced ind - thanks for the reply. im with you on the amount of work. this car is being built from the ground up in my garage... that includes everything from the motor to the paint to the etc...... with the amount of time i already have invested, id rather just fork over a little money to save a big headache. i would really like to make my own mounts, but with the fitment isssues, thats something i can stay away from.

so with the hooker mounts and cts pan you had no issues?

has anyone used the autokraft stuff?

thanks, Tim

bczee

iTrader: (12)

I am currently running a CTS-V pan. There is more than enough room, I fab'd up my own BRP style plate from the template in the Sticky. A $10.00 of 1/4" steel plate, a few hours with cutting wheels, grinders, files, drills and tap followed by powder coating.. and I was done.. all this was done in my garage.
I had a f-body pan on, but it only gave me about 3/8" at the cross member and i was able to pickukp the CTS-V cheap enough, so I when with it. Only con of using the CTS-V pan is that it will most likely hang about 1" below the Cross member.. not a problem for me as I am not slamming the car down anyway.

For the T56 and the trans cross member, easy. cut or grind the weld of the tab, flip it over and weld it back on (from a th350 trans).

I save a lot of money and it wasn't really that hard. Since you have to relocate the engine Frame mount, you end up positioning the engine right were you want anyway. So if your going to move the Frame mount.. they type or style really doesn't matter.

430 hp 70

iTrader: (3)

whats the max stroke that these pans (cts & fbody) can take? what are the stock strokes and bores? id like to combine the max of both so i dont need any overpriced special spec parts. that is unless i find that they make some big stuff in the aftermarket.

thanks, tim

JRracing

iTrader: (35)

I have a carb set up with a vic jr intake and 750 demon carb, msd box which only requires crank and cam sensors and a map sensor. stock coils. My pan has been cut and modified for the cross member.

430 hp 70

iTrader: (3)

Looks like im going to go with a 4.185 bore and a 4.1 stroke on paper for now. id like to go a little bigger on the bore however.

would sbcI pistons out of a 400 fit this motor. i think that as long as the rod and compression height would work it would. the only difference is the crankshaft, but as long as the stroke was meant for the pistons, whats the difference?