Differences in LT-1 heads?
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: Differences in LT-1 heads? (ANTI VENOM)
There is a cast iron head that was used in the Impalas, also of course the LT4 head has different runners. I beleive the baby LT1 which is 262 CID? Perhaps it had a different head as well. But basically all VIN code P 350 LT1 heads are the same, unless they are for the Impala of which those are cast iron. I have heard that some early F body cars were also cast iron.
Instructor
Joined: Apr 2002
Posts: 105
Likes: 0
From: Charlotte NC
Re: Differences in LT-1 heads? (SonnyinVA)
Up through mid 96, the LT1 castings were essentially the same. Around then they started to use a "561" casting which seems to be an Aluminum version of the impala iron head. The 561 has some open areas under the intake runners on the deck, and 'D-9' cast into the outer edge below the two center exhaust ports. It's a bit thinner, but I haven't had issues getting them to peak in the 265-270cfm range. Still, I'd prefer an older casting if youre going all out. For most guys it wont matter though IMO.
