I'm new to third gens and I have a 92 Z28 that doesn't have the original engine in it. What's the easiest way to tell if its a LB9 or L98?

 

You can't really tell whether it's a LB9 or L98, specifically without taking it apart; there's LOTS of 305s that aren't LB9s, and LOTS of 350s that aren't L98s, even though TPI will bolt up to any of them and make them look like LB9s or L98s.

You can at least tell, however, whether it's a 305 or a 350, by the block casting number. It is conveniently located in an accessible spot (NOT), on top of the flange where the trans bolts to the engine, behind the driver's side head. Get the last 3 digits of this number. Those last 3 are also cast onto the sides of the block, and can sometimes be seen from underneath.



All that will tell you however, is what size the engine is. The things beyond that which make it a L98 instead of some other 350 such as a L05, L48, LM1, etc. etc. etc. with the TPI intake just stuck on top of it, or a LB9 instead of LG4, L03, etc. etc. etc., include the head castings, the pistons, and the cam. Those require a little disassembly to determine.

 

Thanks for the info.

 

You can pop a valve cover and get the head casting number. That combined with the block casting will tell you a good bit about the motor. Like he said not the complete story without knowing the cam and pistons but knowing the heads and displacement can give you a pretty good idea of what you're most likely working with.

 

Thanks again, I'll check that out as soon as I get a chance.

 

If you cant see the number on the back by the dist. a complete possibility, the AIR tube DOES wrap around the back of the motor on mine (and other member's cars) and completely covers it up. You can pull the AC compressor and look for the number here stamped on the topside of a pad located here:

http://rides.webshots.com/photo/2084...84999611OwKNCs
(thanks camaronut79)
That will give you number like V1128ATF(that's what mine said). Take those three last letters and go here:
http://www.nastyz28.com/chevy-engine-code-stampings.php
and look it up where it says "Small Block Engine Suffix Code Menu". This will not only tell you what CID it is but what it came out of and the year.

 

Good info. Thank you guys.