LT1/LS1 into '55 Chevy

I’m trying to help my dad out with a project since he’s physically and mentally not capable to take a project like this on, that project being a fuel injected, 4 speed automatic set-up in his '55 Chevy which is currently running a 350 carbed, and turbo 350 trans. I have seen LT1 and LS1 engines along with trans, wiring, computer, and front end accessories sell for $2k-4k.

I know there are parts out there for motor mounts, tranny mounts, exhaust isnt a problem…but my question comes with the conversion to fuel injection.

Assuming the engine wire harness and computer are complete, what more is involved to get this to work in the '55??? I would assume it’s not much more than hooking up power to everything???

Also, if I go forward with this…who are the people on here that know their shit when it comes to conversions like these??? I can only read so much, I’d really like to talk to someone who’s “been there and done that”

Thanks, Mike

Yeah pretty much both the LS1 & LT1 have underhood computers (PCMs). The whole wiring harness can come out with the engine and that is usually how places like Hawks sell engine, harness, PCM, tranny combos

You will have to do some splicing like where the stock harness would plug into the vehicle body harness to power things like the fuel pump via a fuel pump relay.

Painless as well as a few other smaller companies offer LT1 & LS1 harnesses brand new with complete instructions and every wire marked. However these come at a premium because you have to do no research, just read and hook up. Any other questions let me know

Don’t waste ur time with an LT1 Mike, GO LS1 or go home.


megasqirt, LS1 t56. stairt axle, would be killer

keep the carb, ditch the auto, get a 4-speed and have a real rod

the world doesn’t need anymore of this fuel injected automatic Boyd stuff.

Um…thanks for the opinions guys on how my dad should build his car but I’m pretty sure that’s not what my post was about. The old man simply wants something he can take a 3 hour long drive in to the cabin for the weekend, hence an overdriven automatic. He has knee problems and therefore an automatic is necessary. He also wants fuel injection for the ease of operation, he’s long past the point in his life of wanting to open a hood to make adjustments.

J&J, thanks for your help:tup:

Ok I gotcha. Bad knee is a valid excuse for an auto. Having a vagina is not.

There are some nice GM truck takeout setups on ebay. There is a yard that specializes in GM that has a nice setup. 5.3 and trans with computer and harness and pedal rheostat and everything for 5k plus freight. Prob not a bad deal if it all works good. The only thing I see you’d need is an air cleaner, fuel pump, and the proper VSS.

Also, as was mentioned there are lots of premade LT1 and LS1 kits and lots of hard parts out there in swap sheets and ebay and stuff. I tend to favor my labor for cheap, but a plug and go from Painless or a similar outfit may be well worth the expense.

Thanks! Some good info there and that ebay auction seems to cover a lot of the bases. This car will be a cruiser…nothing more than that, and a modern drivetrain would suit him well.

Of course…a cam swap and a few other bolts ons wouldn’t be out of the question, I’m sure I could talk him into that:headbang:


I need to see pics of the double nickel.

Here she is…

There’s a very good chance that this will be receiving an LT1/4l60E drivetrain over the winter…either from a 9C1 cop car or a Trans Am, we haven’t decided which vehicle to pick from. I can’t wait, even with this dog of an engine and the 3 speed the car is a an absolute blast to drive:)

5,56,57’s had front and rear engine mounts instead of on the side. You might want to check Mike. We put a later 350 into a buddies 56 and bought a kit with a crossmember to put side mounts in it(think it was a transdapt kit) wasn’t the funnest thing to do

True…which is why this notion (pic below) has really sparked my interest since one of the engine options would actually come from a '94 Caprice 9C1 that is still in drivable condition. The text doesn’t go into too much detail but the short story is is they took a '56 body and dropped it onto the Caprice frame…therefore using the eng/trans/susp/rear end/brakes/etc. I’m just not sure how involved this swap would be…all I know is it would be pretty nice to drive!!!

There are a ton of resources for Tri-Fives. has been around forever. But there are a ton of forums and groups that could help you with the swap. I’ve seen it done plenty of times. I do believe they have special motor mounts for swaps since the motor has to be pushed away from the firewall.

Nice 55 though :tup:

Yeah, we’ve done some business with Classic Chevy…they’ve got a lot of parts that for sure! I know there’s web forums out there and the swap has been done before but I can’t seem to fin these forums or any write-ups with some good solid info on the swap.

Thanks for the compliments:)

I want to check this out when you get it in Buffalo. My first car was a 57 Chevy 2 door sedan Bel-Air. I miss it.

You better document the hell out of it and post up pics! :wink: