LT1 conversion

[cpratt]

I have a lead on an LT1 from a mid '90's Camero with 97k on the engine, complete with exhaust manifolds, flywheel, wiring harness and computer, starter, electric fuel pump, etc.

I'm really contemplating getting rid of my over built sbc400 currently in the truck for something fuel injected and maybe get a couple more MPG.

Seeing as I'm already setup for a small block...any big hangups or show stoppers? I know the swap has been done many times, just curious if anything is much different between an old 400 and newer LT1.

Thanks.

 

[JONNYFJ]

I have looked into an LS1 and there was no major set backs to the conversion. Motor mounts are the same. You might have to mod the bell housing not to sure, I know that guys are paying upwards of ten grand to have it done with a stock LC and a new LS1. I would like to do it, but but can't see put ten G's into it. I am sure it can be done but I am never home more than a couple of months, So doing it myself is out of the ?

 

[cpratt]

there is a difference between an LS1 and LT1 I believe. The LS's have slightly different engine mount configurations... Something comeing with everything needed I would think would be a fairly easy swap, considering the truck is already setup for a SBC.

Thanks though, and thank you so very much for you service. I have a couple buddies in the Army, one sniper in the Rangers and one Green Beret. I have all the respect in the world for you.

 

[iaintscared1969]

Just need to have the CU flashed and the wiring harness modified. Mounts will be slightly different but an easy fix only as far as how they mount to the block itself. On some versions they changed the bolt pattern on the engine. Everything else should bolt up.

 

[ToyLet503]

I helped a buddy do this converesion in a J**P and it is not as straight forward as it seems at the start. There is a vehicle speed sensor that will cause some problems.

If you can get the vin # from the donor car and call Howell Engine Development in Michigan as they make a harness that you can have built to suit your particular situation with only needed conections and eliminate alot of exta wire.

If you send them your ECU thay will disable the factory anti-theft curcuit reflash it and send it back ready to run.

As far as the mechanical side of it he used an SM420 and a 1994 LT-1 from a Camaro which all bolted together with no drama, we did make custom mount for the motor and trans as it was put in a CJ5.

He did get ahold of a conversion book which helped alot and i can get the name of it if you want.

I hope this helps and Good Luck!

 

[TLCHopII]

I am running a mid 90's LT1 (vette motor stroked out to 383) with a TPI set up and an sm465. I'll be pulling the tranny on Fri or Sat so if there is anything specific you wish a picture of or some measurements post it up & I'll get what I can!

 

[inkpot]

Howdy! Also, I'm guessing you have the older narrow pulleys running all your extra goodies. The LT1 will have a serpentine setup, which you can keep or swap out. Wish I was a little closer, as I could use a 400 in my Piggy. John

 

[TURNMEOVER]

Be shure to get a vss it is a must. Call jim over @ downey they are th only ones that sell a vss for your application. And unless you are very electricaly compitent I would highly recommend A harnes from howel or painless. There is a lost of s*** in that harnes that is garbage but most is verrrry important .

 

[theo]

I bought my vss from Jags that run. The price is up 20 bucks from when I bought mine but it's still less than Downey.

The wiring harness has quite a few wires in it. But it's not insurmountable, just tedious as hell. You'll need an ohm-meter and a wiring diagram for your ECM. A decent repair manual for the donor car should work fine.

Something that doesn't come up that often is fuel delivery for a high pressure system like that. I have TBI and I worried about cavitation so I built a surge tank, but I think quite a few folks just pump straight out of (and back into) the stock tank. The issue is how low can you run your tank and not cavitate and overheat the fuel pump.

 

[Downey]

WOW, my turn:
(a) Rad hose I.D. will be different. The old engine used 1.5 hose top, 1.750 hose bottom. LT-1 will need 1.375 top and bottom.
(b) LT-1 could have same or different motor mount bolt pattern

on block

(c) Here's the VSS criteria; If 85-89 TPI you need a 2 pulse VSS. If 90-93 TPI you need a 4 pulse VSS. If 94+ you need a 40 pulse reluctor ring and magnetic VSS. Yes, we have them all.
(d) What tranny are you using??? Tranny choice can bring up some other issues.
(e) Call me well before dealing with Howell or making any other ECU/Harness choices!!!!!
(f) Get Downey freebie V8 Inst. Book, especially important for ECU and Alternator wiring. PM your address and I'll get one to you.

Jim

 

[cpratt]

Thanks Jim. I have a 4pulse VSS from you guys, but seeing as this is from a '95, looks like that would need to be swapped. Tranny is a stock 4speed, not sure which adapter was used, PO did the conversion.

Are there downsides to this engine? I've read some complaints about the distributor can get condensation inside?

 

[inkpot]

Thanks Jim. I have a 4pulse VSS from you guys, but seeing as this is from a '95, looks like that would need to be swapped. Tranny is a stock 4speed, not sure which adapter was used, PO did the conversion.

Are there downsides to this engine? I've read some complaints about the distributor can get condensation inside?

Howdy! So what did you do to "overbuild" your 400 sbc?? John