77 trans am LS1 swap or not?
#1
Teching In
Thread Starter
Join Date: Nov 2008
Location: Canyon Texas
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
77 trans am LS1 swap or not?
Hey guys i have a 77 trans am that was my first car and im looking at droping a new motor in it but i cant decide and what motor. I am thinking LS1 (4L60 or t56 depending on my budget) or rebuild the 400 with a 700r4 swap. The ls1 has the dependablilty, and modern restorod style but the 400 would be more true to its roots. What do you guys think?
this is the car
this is the car
#3
TECH Regular
Join Date: May 2005
Location: Bay Area, CA
Posts: 406
Likes: 0
Received 0 Likes
on
0 Posts
If its an original 400 car I can see the debate. With a set of KRE heads, a roller cam and one of the new Holley/FAST/MSD fuel injection kits the old 400 would run pretty damn well and would be great with a T56 or a 700r4/200r4.
Tough spot to be in.
Tough spot to be in.
#5
On The Tree
Trending Topics
#8
10 Second Club
What heads are all ready on the 400? They don't look like the old 6xs. If you plan to ride it alot or want to make big power I'd drop in a LS but if its going to be a every now and then car stay 400. Those 400s like fuel lol.
#9
Teching In
Join Date: Jul 2011
Location: Detroit Metro
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
I think you should stay with the 400 and rebuild it. You can make good power out of it, but you will use more fuel! The 400 just looks a lot better under the hood than an LS.
#10
I have been pondering the same thing... but... mines not number matching... and a 77 clone... so... i think the LQ4 is going in...but with a 700r4 that i have had built for the 455 already in place...hoping the seat of the pants feel is the same...
Last edited by Cecil07; 12-31-2011 at 07:20 PM. Reason: poor education
#14
TECH Enthusiast
iTrader: (7)
Easy choice....swap in LSx power! But the real answer is do what you want to do, not what you think others would want. As for future resale, I can't imagine a nicely done conversion wouldn't be at least as valuable as an original. While you don't see that many T/A's anymore, they weren't exactly limited production, and w/factory power levels were not all that desireable (IMHO). You decide!
#16
12 Second Club
iTrader: (2)
I am in the same spot with my TA kind of - yours is a much more original car so I can see it being a painful decision for you.
mine is an 81 that was a turbo car with a 72 nose so its a mongril but really rust free , the 400 in mine is of unknown origin and I just listed the complete engine with headers ,high rise , edelbrock intake and turbo 400 locally on CL as well as the turbo wheels & tires.
I am going year one 17" billet honeycombs and likely something LSX , my thought on that is I could pull the 400 and nowadays you can buy aftermarket crank & rods for about the same price as aftermarket crank & rods for a sbc now that eagle & scat are making stuff , it would be a lot stronger than even the best stock castings and make plenty of power but at the end of the day its still going to be a heavy **** fuel pig of an engine so I said screw it and listed the drivetrain knowing once the engine bay is empty i will commit to buying up the necessary goodies to bring the car into the 21st century engine wise
good luck making your decision , just keep everything so you could go back if you regret it allthough I doubt you would
mine is an 81 that was a turbo car with a 72 nose so its a mongril but really rust free , the 400 in mine is of unknown origin and I just listed the complete engine with headers ,high rise , edelbrock intake and turbo 400 locally on CL as well as the turbo wheels & tires.
I am going year one 17" billet honeycombs and likely something LSX , my thought on that is I could pull the 400 and nowadays you can buy aftermarket crank & rods for about the same price as aftermarket crank & rods for a sbc now that eagle & scat are making stuff , it would be a lot stronger than even the best stock castings and make plenty of power but at the end of the day its still going to be a heavy **** fuel pig of an engine so I said screw it and listed the drivetrain knowing once the engine bay is empty i will commit to buying up the necessary goodies to bring the car into the 21st century engine wise
good luck making your decision , just keep everything so you could go back if you regret it allthough I doubt you would
#17
On The Tree
Join Date: Mar 2009
Location: Commiefornia
Posts: 133
Likes: 0
Received 0 Likes
on
0 Posts
If you're never planning on selling it then do what you will enjoy most. If you want to have a better driver then definitely go with an LSX, although I'd do a 402 stroker so at least you're in the right ballpark on cubes. If it's not the original 400 then it's easy, LSX swap. But if you rarely drive it and it's matching numbers I'd probably leave the 400 where it is.
#18
Teching In
Thread Starter
Join Date: Nov 2008
Location: Canyon Texas
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
just going thru my old threads and forgot about this one. Since so may years have passed since i originally posted, i thought i would update. The car is not a number matching car, if it was i would have left the original motor. VandykeT/A asked about the heads on the old motor, you are correct they are not the 6X, they were 1970 #16 heads. I did not go with an LS but rather kept the Pontiac a Pontiac. I ended up with a Butler Performance 468, full roller, with edelbrock aluminium cnc ported heads, ceramic dougs headers, torker intake, and an msd ready to run distributor