LS7 Head Info Needed

[GTO_DON]

The square port heads have 1 small hump in the front identifying as the high horse head.

[mockingbird812]

Pantera,

I realize that the casting symbol is usually found on SBs, but LS6 heads (291's) from 1970 had characteristic single humps in the casting flash line. The hump I was referring to is at the front of the head (facing the fan). It is a quick (although not conclusive) ID w/o looking inside the valve covers. I found it odd that Colvins does not call out this hump in the description of this head. One had it the other didn't. I just can't figure out why it has it.

Sam

[mockingbird812]

I guess I am a bit confused. Colvin's calls the heads I looked at the other night (3994026) as being for a 1971 Chevelle LS6 454/425. But there never was such a beast (at least in production). So if what COPO Anders says "In 1971 the LS-6 was only available in the Corvette. It used aluminum heads." Then what application did the heads I looked at have?

Sam

[Pantera]

This is what Mor-tec says about the usage of these heads

3946074 69&71 rect OPEN 'Aluminum, ''69 427 L88, ZL1, 118cc chamber & '71 454 LS6, "round exhaust port"

3994026 71 rect OPEN '454 LS6, 118cc chamber

6272990 70-up rect OPEN 454 service replacement, used on some MKIV crate engines, 118cc chamber

I just went out and looked at some heads that I have and after quite a while looking I think I see what you are refering to on the hump. I only have HP heads # 840 # 990 #208 here at the house and they all have the hump. It is about the size of the end of your finger?

I learn something everyday on here. I never noticed these before. I have no oval port heads to compare to.

If someone has a low HP motor check and see if this is different on your heads to see if this is correct?

[mockingbird812]

I guess I am a bit dense here. The application of these heads (3994026 '71 rect OPEN '454 LS6, 118cc chamber) are supposed to be for a '71 LS6 CHEVELLE, but there was no such animal. So what,if any, car were they used in?

Sam