I have a question concerning crate motors.  gmpartsdirect.com lists the LM1 350 engine at 250hp/304ftlb for $1,292, and the HP 290/350 with 290hp/326ftlbs for $1652.  Both need intake, carb, distributor, starter, waterpump, ect.  Anyone know what the difference is in these two engines which accounts fo the 16% increase in HP.  Is it just a different cam, or are the heads different?  Would it be better to buy the LM1 and use the $360 difference to replace the cam, and pocket the difference.

Same head specs...same compression ratio...different camshaft...different crankshaft. Both have 4-bolt mains on the crank. The 290hp has a nodular iron crankshaft (stronger) where the other has a cast crank.

If you buy the LM1 and change the cam, you'll lose the warranty since you modified it.

Depending on your finances, give thought to the 350HO/330hp engine. It gives the most bang for the buck.

I'd gotten my zz4 from Jeg's ... complete engine minus starter/carb/exhaust/etc.... best i recall, was around $3800, but that was 4 years ago...or was it 5?... anyhow i'll paste the specs

I bought 2 out of 3 of my vettes for less than the price of a ZZ4, but one can't help but lust for an extra 100 + horses under the hood. I'm hoping to go there myself some day, but that much money would buy a lot of improvements on the other cars.

well guys im in the same boat To start off with the good point, my dad gave me the 80 4speed vette. It has 80,000 miles on the rebuilt motor. I took off the intake to have it polished and looked inside the heads and saw build up around the bottom of the valves, now I want a new motor. Scared to bye allum heads, dont know  if seals will blow. The motor is not smoking or burning oil. should I just ride out the waves untile Im really able to afford a good motor?