Is there a good gm crate motor that i can replace my stock L98 with. Maybe also with a GM hot cam. I just dont wanna throw any crate motor in and end up with less HP.

 

There is really no factory or GMPP direct replacement motor for the L98. Most one piece RMS 350 engines with 87-up bolt pattern heads like your 87 are truck replacement engines with swirl port heads on them and flat tappet truck motor cams. The others use Vortec-style heads (FastBurn 385, for instance) or they use old-style 85-down intake pattern heads with no EGR passages (ZZ4).

A later model Vortec 350 short block is almost identical to your L98 bottom end, though. If you can reuse your existing heads and cam in it, you would have basically an L98 clone. A bolt-in.

The HotCam has quite a bit more lift than a stock head can take though (.525" with 1.6 rockers or .490" with stock 1.5 rockers). Still too much for unmodified stock heads and springs. If that's what you want you will probably be modifying your existing L98 heads to take that much lift OR looking at some aftermarket performance heads. And that cam is likely a bit much for a stock TPI intake as well.

 

Great this is what I wanted to hear! I wanna buy a short block or rebuild my existing bottom end. Put alum heads (maybe AFR) and cam, new injectors ect...and the list goes on.