1991 RS LO3 5M

I have been shopping junkyard pull-out motors.
I have found prices from $700 to $2500 for '98 up 5.3, 5.7, 6.0 etc.
I have read about LQ4, L30, L33, Lm7.
It seems to me that spending $1000-up on my existing 100k LO3 might not be the best spent money.
Has anyone made a similar swap.
Could this be an impossibly expensive project or should I be looking at older engines for better compatibility with my '91 auto?

 

There is a whole section on Thirdgen.org dedicated to the LS1 engine swap into a Thirdgen.

https://www.thirdgen.org/forums/ltx-lsx/

It all depends on your goals as what is the best money spent.

 

Thank you for the direction.
As I am new to this site, I haven't been able to see it all.
Thanks again.

 

Way to not answer Doug...

What kind of budget are you on? There is no question, hands down the LS series motors are better. The big question is going to be if you can get it done on your budget. Most of the motors that I have seen that are really cheap, are higher milage 5.3L's. They aren't a bad motor, but the small bore limits their potential. The 5.7's get a premium because they are "Corvette" or "Camaro SS" motors. So really the 6.0L is probably what you should be looking for.

If you budget is $1k, I would shy you away from either route, and suggest that you save money for a while until you can afford to really do this right.

The only other thing to consider, is if you are going to try to upgade to a T56 at the same time, if you are, you might be able to find a combo LS1/T56 or a whole wrecked 4th Gen to get. I would think that if you hit the auction, you could get a rear-ended totaled out LS1 car for $2k. That would get you most everything you need to do the swap. Then it is just a matter of lots of electrical fun. Then you might even be able to sell of a bunch of parts to help pay off the upgrade.

--John
(I just couldn't see you go without an answer)

 

If his goal is a dependible daily driver that gets descent gas mileage, 1k will buy him a rebuilt 305 and everything he needs for the install. It all depends on his goals.

In case you didn't notice, he said 91 auto, not 91 T-5, so I wouldn't even assume he is going for a T56 swap. Though the parts car is probably the best advice if he really does want to do the LS1 swap.

The 4L60E swap is a whole lot cheaper then the T-56 swap, as the T56 is worth as much, if not more, then a used LS1 in a lot of cases.

Unfortunately you gave no information on your actual budget and goals, which is why all the answer I gave was "it all depends on your goals".

 

you can also go with a Crate motor if you wish, sometimes getting a crate motor is cheaper than having to rebuild an engine from top to bottom & having to take it in to a engine shop to have it clean & balanced.