Are all the short blocks on all of these motors interchangable? For example if I could get a great deal on a lmm motor, can I just put the top end from my current lb7 ( to eliminate all the emissions b.s.) and just use the bottom end from the lmm? or would it be more practical if I just drop the whole engine in and efi tune it? If any of you engine builder gurus can chime in, that would be greatly appreciated. Thanks in advance

im sure someone with chime in with the specifics... but i think for the lbz and lmm they run a totally different compression... so prolly not.. lly maybe?

i would get efilive and tune as needed, currently LB7/LLY hybrid is looking good for injector problems. LBZ+ stronger blocks to match factory HP ratings.