Join Date: Jan 2007
Location: Fort Worth, Texas
Head casting #s for LT1 and LT4
I picked up a set of aluminum heads that have a casting # of 12551561 - does this # mean an LT1 or LT4 head? I can't find a listing for this #, L99, LT1 or LT4. I assumed, as did seller, that they are LT1s from a "96 'vette.
The heads are in transit so I can't just go measure the valves. I've seen the 1255 on a lot of LT4 parts.
'11 GMC Sierra
'94 Trans Am 383 LT4, A4
690 heads, TrickFlow Elbow, Lingenfelter CAI, Accel 32#, Summit 58mm TB and bypass, Edelbrock LT4 Airgap, LT4 notsoHotcam / 1.6 RRs, MSD Pro-billet, Blaster, Superconductors OTVC, 6A box, Aeromotive Adj FPR, 160*, LT4 KM, Pacesetter LT / ORY, Magnaflow catback / bullet, PCM for Less tune
BMR SFCs,LCAs, PHR and TQA, S60 w/3.54s
Coming soon: Lunati 60122, 3200 stall
American Legion Post #569
The few, the proud, the slow. The LT4 Owners