OK, after doing some research I can't decide which is better. Should I resleeve my LS block, and bore it to 84mm, or should I use a b20 block and use some nicer sleeves in that? I am planning on going all motor, POSSIBLY with nitrous. What should I use, b20 or b18b?

 

Since you already have the b18b block then I would say resleeve it. You will be that much farther.

 

The thing is, a buddy of mine owns a shop, and has and regularly gets motors, so I can have either no cost to me. Its either keep b18b, or trade for b20 for free.

 

Damn, good buddy ya got there.
Its either:
-sleeve the b18 now and have years of abuse without the slightest thought of cracked sleeves
-or-
-put a b20 in now hoping that it can take the abuse that you are about to dish out to it. if it cant, then you will have to take it out and resleeve it anyways.

 

Would I see a HUGE benefit from a sleeved b20 vs. sleeved b18b?

 

The B18b is 84mm stock! B18b, and B20 blocks are the same, its the cranks, and internals that are different! I ran about 5000 miles on my fully built N/A B20/vtec, and the sleeves are cracked (stock bored to .20 over)! So if you are going to build either one, SLEEVE it!! (If you are wandering B18a's are 81mm)

 

stick with the lsvtec, why add extra weight with a b20 block, plus all the extra work whether you have a buddy that owns a shop or not.

 

Thanks guys...... I think im going to end up with LS/vtec

 

Someone here is full of **** and I think I know who it is...^^^^
The b18a/b and the b20b/z are the same blocks except for the bore. The b18a/b has an 81mm bore while the b20b/z has an 84mm bore. They have the same cranks, 3B.
No because they become the same when you have them sleeved. What I mean is you can have either one sleeved to just about any bore you desire.