dont be so quick to toss the lt1, its a great motor with just as much potential as the ls1 if done right, cost to switch to ls and build lt1 to hp of ls should be close to the same. need to know more about the motor you have and the story behind the breakdown. why dont you want to use it? what is wrong with the block you have? how bad was it overheated? it may be you can replace the rings and bearings, rebuild or replace the heads and your back on the road. 84k miles on the lt1 is just getting broke in, the only thing you need to worry about is if the antifreeze has ruined the bearings and if the block is cracked.
i dont know if your some kind of super mechanic but 5 hours to change a 4th gen motor is not realistic unless you have all the right tools and a couple knowledgeable helpers. i would say a long weekend and you could do it so long as nothing goes wrong. it would be nice to know what your budget is as well. its hard to figure without knowing the resources you have at hand.

 

craby i pulled ans swaped mine in a little under 5hrs by my self and i puilled mine out the top 5 hrs is not hard to do
also i seen a set of corvette heads on criagslist with 2.00 intake and 1.55 ext for 300 in illiniois

 

id say youve done it before and/or your a super mechanic. lol. your on here so it must be the latter. thats pretty good time so you musta worked straight through without any problems.

 

yeah you must be the most amazing mechanic ever...especially to pull it out the top that fast. had 3 of us working on mine and it took us 5 hours to get it out the bottom

 

wasnt that bad it was easier to do it that way then pull it ot the bottom when i pulled mine it took a little over 2.5hrs to get it out and the say maybe a little les when i put it in by my self the only hang up i had was matikng the trans back to the engine and that was a 10 min ordeal it really is not a hard task and im no super mechanic by any means

 

bigmike95Z28 dude itis n ot uncommon for these motors to warp the heads they are a 10.5:1 motor stock so that make for extra heat any way and aluminum tend to warp under extended heating and cooling cycles have a machinist look them over and see what he says you what have to worfry about valve to piston clearence with 1.5rr cuz the stock pistons have relief cuts in the top of them to accomadate the valve and the 20 thousandths that they'll probably take of is not going to really make a diferance it will bumb your compression up to 10.6:1 so not a reall big deal

 

Man, you need to go into changing lt1 engines. If you do it that easy and fast you could make some big bucks.

 

I just looked on craigslist and there are several lt1's for sale. I saw a lt1 with 6 speed transmission and 53,000 miles out of a camaro for $1,300. That was just the first one i looked at. That would be a great deal with the tranny too.

 

What happened to the o.p.?
Shaving the heads 20 thousandths is going to bump the 10.5:1 c.r. up to 11:1. It's not a minor change, and premium gas will be a requirement. But .020 is a bit much to clean up a head, .005-.010 should usually do the trick. Thicker head gaskets could be used to compensate for the shave to keep the c.r. the same, if he wants to. And because the LT1 has a reverse flow cooling system, the heads get cooled first and are cooled better than how old gen1 style heads get cooled. The heads don't generally warp "just because", as opposed to them warping because of the engine overheating.