Ryans-GSX

I have purchased a 1971 Buick GS Convertible and I am considering doing a LSx Swap on this car as it has sat in a garage for almost 30 years and the motor and trans would need to be gone though anyway. My question is about fuel mileage I already know any of the LS motors will have enough power to pull my GS down the road

1) What LS motor would provide me the best gas mileage ?

2) Are any of the LS motors more reliable than others ?

3) Can anyone recommend any Shops in North Carolina that will do a professional job ?

Thanks for any information on this

LeanPocket

iTrader: (6)

4.8 maybe?

A.R. Shale Targa

iTrader: (2)

This is what I was thinking as well. In 99 they were 255 horse then in 2000
they jumped to 270. Also if the OP finds a 5.3 it would still knockdown around
25 plus mpgs with an overdrive trans and those 3.08 or so gears in the Buick.

Pocket

iTrader: (22)

Any LSx engine with and overdrive trans (T56 has double OD) will net excellent economy. Big fuel killer is big cams. Keep it stock/mild and you're golden

GEN III engines seem to have less problems than DOD/VVT/AFM GEN IV engines, but none are deal breakers. GEN III stuff seems to be easier to swap in general and very common

Cant recommend any place in particular, but Im right down the road in Mocksville and have a few LSx swaps under my belt

Jimbo1367

GEN IV engines are good too. Not all of them have the forementions AFM, DOD or even the VVT. Do your research. (SEARCH function will help)