This may have already been discussed here but I don't see it after searching. I have a 2000 C5 Vette with over 240K on the stock motor. A friend bought a 99 TransAm LS1 about 10 years ago to build for a Porsche 944 transplant. He has offered me a swap, his low mile LS1 for my 240K LS1. Since he is building the motor he doesn't care which one he starts with.
I know there are some differences between the motors, the oil pan, the cam. I figure you folk will know the truth here.
1. If I do the swap I want to make sure I'm NOT losing HP. I really want to add it.
2. If I don't do the swap I will fix the rear main leak in my engine along with some other issues and hope it holds together for 10 more years.
3. The Vette is not a race/track car, it's my road dog.
Oh, and I can't spend a crap ton of cash on this either.
Thanks in advance

 

I'd fix the rear main seal on my 240k mile engine before swapping in an unknown LS1 that's sat around for 10 years waiting on a swap. Labor wise fixing the rear main will suck but it will probably less labor than an engine swap, swap accessories & swap intake manifolds.

Logic, you know what's wrong with your LS1 but don't truly know the condition of the other LS1 plus you don't have much money so risk taking should be minimal. All the tech details of 99 fbody LS1 vs 00 Vette LS1 are irrelevant.

Have 256,000 + miles on my 02 Z28 and fully expect with proper maintenance that LS1 is capable of going ~350,000+ miles.

Also unless this friend is truly trustworthy as close family you're at risk of getting screwed if you swap. Your engine runs who knows what the deal is with his.

It would make sense for a shyster of a friend to offer a swap that "appears" to only benefit you if he secretly knows his motor has an issue. That way he could swap out his bad motor for your good motor while pretending to do you a favor.

 

The pulley spacing is different between the two engines. You'd need to do some swapping around of parts.

 

He's a good guy so no worry there. Thanks for the advice!

 

I agree with 99blackbird. I do think you’ll lose a small amount of power. It may not be much, but the 2000 C5 came with the best factory LS1 cam. It has .500" lift I&E, and tighter LSA (115.5?) than any other LS1. In fact, the 2000 model C5 LS1 is the only MY LS1 that you CAN NOT just bolt in 1.8 ratio rockers, unless you first change the valve springs. Hope this helps.....