Dropping a LT1 into an 81

[jdads2]

Anyone done this lately? I've got the original motor out of the car and plan to restore that one but I wanted an engine with a little more power...what a shock!

This motor has no wiring or computer so does it make sense to put it in or should I keep looking for another. What mods do I have to contend with?

Any help would be appreciated.
Thanks,

 

[Glensgages]

jdads2:
don't put a gun to my head, but I think you'll need a non-computerzied distributor (pre-'80?) for this conversion.
We put an L-46 ('69 350"/350HP) into an '81 Monte Carlo, using the '81 ignition, 12+ years ago, but, if memory serves, the distributor wouldn't pull any advance (? I really can't recall; anybody else?), but once we got a good ignition system & 3.73s, it ran 14-0hs @ 97 MPH in the heat, all summer long.
I'd think with 3.55s or 3.73s, you'd get similar results; sounds like a neat late C3!!!
P.S.: I'm not sure if this swap will screw-up your THM350C torque converter 'lock-up'; you'll have to check with someone smarter'n me (shouldn't be TOO hard...)

 

[bossvette]

which LT-1 ? the early ones should bolt in with a early style HEI like glensgages said while the later are reverse cooled fuel injection types and would require computer control.
Anything is possible you have to know what you are starting with and where you want to go with it. A late model LT-1 with a OD trans and you will have a great running Vette

 

[Stallion]

If you drop in an early LT1, how would you be able to use the HEI? It was introduced in '75 (I'm pretty sure). You wouldn't need to do anything to make the ignition breakerless? You could just pop on an HEI for an LT1?

 

[Glensgages]

:duh
I'm sorry; when I saw him say 'LT1', I'm sooooo old, I thought he meant a REAL LT1, like from a '70-'72, not a later-model EFI-version.....:confused
I can't offer any help with these 'newer' motors; in fact, if my '82 wasn't so pristine & immaculate, I'd be dropping a ZZ502/THM400 in it, just to get away from the Cross-Fire/ECM/700R4.....
(Roseanne Roseannadanna voice "Never mind..."

 

[MaineShark]

If you drop in an early LT1, how would you be able to use the HEI? It was introduced in '75 (I'm pretty sure). You wouldn't need to do anything to make the ignition breakerless? You could just pop on an HEI for an LT1?

You would have to replace the original distributor with an HEI distributor

The differences are all "up top" - the part that the engine sees is the same...

Joe

 

[bossvette]

I guess we will have to wait and see which LT-1 jdads2 has, either one will work but the early one would probably be an easier swap

 

[jdads2]

...mid 90's LT1. Of coarse it's the more difficult of the choices. I'm willing to bet that after getting all of the after all the new parts needed to make this engine swap fit properly I'd have spent the same amount than if I drop in a rebuilt engine. I have the opportunity to pick up a 400hp, sb406 for $1800, minus carb. Eseems to me that I should stop foolin around and just get that engine.

Thanks for the replies,

 

[Stallion]

Ahhhhh, I also thought you were talking about the 70-72 LT1s.

 

[bossvette]

jdads2
Mid 90's LT-1 you would need electronics (I used holleys Commander 950 and am quite pleased with it) High pressure fuel pump and plumbing. I am not familiar with an 81, but here is a link to a TPI swap in an 82 which should be close
http://home.att.net/~ncarboni/NC82.html
If your 81 is a carb car you may have to swap to an 82 gas tank the 406 swap would probrbly be the easiest and cheapest.
keep us posted on your progress