Small Block & Big Block Chevy Specific - LS6 heads

Picked up a set of heads yesterday. One is a 3994026 the other a 6272990. They appear to be exactly the same head. Anyone know if that's true?

Trying to decide if I want to use them or get some low cost Aluminum heads.

They are for my 454 powered 73 Nova that now has early 396 heads. It's been together for about 20 years, time to freshen it up. Might as well change the pistons and get some better heads on it.

Al

We have a set of these on my wifes 489 and love them.

http://www.jegs.com/i/Brodix/158/2061000/10002/-1?parentProductId=755729

http://www.jegs.com/images/photos/100/158/158-2061010.jpg

We have a set of these on my wifes 489 and love them.

I have a set of Big Brodies on my 73 Camaro. This is a mild street car, runs in the very low 12's with no PA's. I may build the engine for the 73 Camaro as 9.00's are tough on me. The damned NHRA license is putting me back about a grand now.

Al 73 Nova 454, TH350, 9" Ford.

http://www.youtube.com/watch?v=Zh6CT_mwGuI

She is running high 10's with these. Should go quicker but think the convertor is to loose. Have a TH400 and 3.90 geared 10 bolt. I would use these on the street also. Oval port, large combu chamber. We have about 10.5 to 1 with a 1/4" dome piston. They are a direct bolt on also, makes it that much nicer to have. :)

I hate to go off topic, but do you two think a set of BB2's would be too much head for an NA Street/Strip 496 that only wants to spin to 6500?

No, that's all we spin my wifes 489. Has huge amount of torque of the line. I guess you are talking about oval port heads?

Oh yea, the ONLY modification that we had to make was to grind the header flange to clear the 4 head bolts at the bottom.

She is running high 10's with these. Should go quicker but think the convertor is to loose. Have a TH400 and 3.90 geared 10 bolt. I would use these on the street also. Oval port, large combu chamber. We have about 10.5 to 1 with a 1/4" dome piston. They are a direct bolt on also, makes it that much nicer to have. :)

She's running high 10's in what? How much does it weigh?

My Nova is a street car, has a hydraulic flat tappet cam, and so on. It run's .3 of a second quicker than my LT1 street car:) .3 seconds for 110 more inches:) But I have to admit, no one will try the Nova on the street. It just looks and sounds lot faster than it is.

Al

71 Camaro, 3200 lbs with her in it.

No, that's all we spin my wifes 489. Has huge amount of torque of the line. I guess you are talking about oval port heads?

Oh yea, the ONLY modification that we had to make was to grind the header flange to clear the 4 head bolts at the bottom.

Actually they are the old casting BB2 rectangle ports. (I got them for a killer deal, a $500 deal.)
http://www.brodix.com/heads/bb2.php

They have a mild port, but they need to be cleaned up and flow tested.

My build is going to look like:

Intake: Victor Jr with TB 38783 or the Pro-Flo XT with a 92 MM LSX T/B
Heads: BB-2 Rectangle Ports
Cam: Something along the lines of 111+3 255/259 .690/.670.
Rockers: Gold 1.7's.

18 CC Dome Pistons, 113 CC Head, .027 Head gasket. (11:1) I will be using 80% 91 and 20% E85 for a very nice 93 mix. (Damn midwest!)

I use Engine Analyzer Pro to go over my selections(I know, don't trust programs but it has really helped me learn about camshafts.), I keep trying to maintain a good DCR and idle vacuum.

My projected DCR should be 7.56, and my idle vacuum should be right at 9"HG

Picked up a set of heads yesterday. One is a 3994026 the other a 6272990. They appear to be exactly the same head. Anyone know if that's true?

Trying to decide if I want to use them or get some low cost Aluminum heads.

They are for my 454 powered 73 Nova that now has early 396 heads. It's been together for about 20 years, time to freshen it up. Might as well change the pistons and get some better heads on it.

Al

Hey Al to answer your original question...those heads are basically the same, the 6272990 is a service replacement head and also found on some MarkIV crate engines. The 3994026 is a 454 LS6 Rectangular Port Open Chamber Head. Both with 118cc Combustion Chambers. If the came off the same engine, the one head was replaced at some point.

Actually they are the old casting BB2 rectangle ports.

Hers are Oval Ports.