Jeff H

The Corvette has different LT1 heads than the F-body. The iron LT1 heads are from the same casting as the Corvette aluminum heads and have better flow. The Impala SS LT1 with the cast iron heads have a different cam due to more weight and needing more torque down low. The Impala engine also uses a smaller diamter MAF compared to the Corvette and F-body.

arnie

Ya, already mentioned here.

The iron heads are the same as the Corvette aluminum LT1 heads, but the F-body aluminum LT1 heads are different

Incorrect, and incorrect. LT1 aluminum is LT1 aluminum, vetter or F body. Iron is not the same as an LT1 aluminum. Ever see an iron head and an aluminum one side by side? The chamber is probably the bigger physical diff of any aspect of the two heads.

As for which head is better, the iron will hold the heat better which will make more power at the top end.

It is not only you, but it would be nice, if the focus of this thread can be on original ?. Which is better flowing head?

Both heads can be ported to flow the same so that is a moot point.

Since I disagree with that statement, if you could provide links to substantiate that claim, it would be great.

Steve0

Not only do the Iron headed LT1s have a half point less compression, but their cams are a little less agressive, .450/.460 (int/exh) in the Fbody vs. .417/.429 (int/exh).

Z95m6

I thought about using iron heads in my rebuild when i had my motor out cause i had heard about the better flow over aluminums. From what i've heard the 96-97 aluminum LT1 head is the same port design as the iron so they have the same flow. What really made me stay away from the iron heads besides the fact that a lot of people won't port them is i believe they have a different plug angle into the head. i was to worried that Fbody headers wouldn't work then i would just have a nightmare trying to get everything to work.

arnie

Unlike the aluminum angled plug,the iron has an old sbc style straight plug orientation. I personally could not figure out why GM would regress backward, with the use of the straight plug. I believe though, that it has to do with the combustion chamber shape, which is obviously different, after a quick glance of same, from the LT1 aluminum. Ya, I know, I didn't disclose much.

arnie

Happened to review some previous posts/threads regarding this discussion. FWIW, Phil (SkarodoM) posted the LT1 (early casting..92-95) aluminum head had far more potential than the iron head, regardless of having less flow oem, as cast. FFT.

BlueCamaroZ28

The iron Heads will install into the F-Body without any problem with plugs angle.

I just installed a 1996 Impala SS LT1 engine into my 94 Z28. It was a straight forward swap. I used the Z28 A/C, alternator bracket. The heads are iron heads. Just swapped knock sensor to 1994 knock sensor to clear the check engine sign. No problem with plugs angles at all.

terlox

If I could butt in and ask an obvious question...

LT1's out of B-body cars used iron heads correct?

LT4 vette's use aluminum heads?

What does my '95 LT1 use?

Eddie95Z28

Assuming you "95 LT1" is a F-body they would be aluminum heads....

terlox

Thank you.

arnie

If in doubt, try a magnet test.