ported heads

[gtxrt]

someone has a set of ported heads he calls them stage 3 and the stage 4 he calls race heads. would the stage 3 hurt bottom end power. still has the 2.08 1.74 valves. only have 2.94 gears and 2200 stall converter.

 

[Lefty71]

IMO, there are no 'standards' for these terms, although there probably should be.
If by, stage-3, he means final max wedge ports sizing and shape, then yes it would hurt bottom end, and you would need an intake specifically made to use that head design.

Pix, and more info may help with your query.

 

[gtxrt]

photos

 

[Lefty71]

Casting #?
What intake?

 

[gtxrt]

Casting #?
What intake?

915 rpm performer 224-224 duration cam 525 lift

 

[PRHeads]

Trying to not be a smartass, but the truth is…….there is only one way to know for sure how those heads would compare to your current heads, on the current combo.
And that’s to try them.

If you get them, it appears they have aluminum retainers.
It would be wise to change those out.

 

[gtxrt]

Trying to not be a smartass, but the truth is…….there is only one way to know for sure how those heads would compare to your current heads, on the current combo.
And that’s to try them.

If you get them, it appears they have aluminum retainers.
It would be wise to change those out.

they do have aluminum retainers but he has to change them to get to lower spring pressure from 1.8 to 1.9 installed height. would be 130 seat 300 open instead of 150 seat 325 open he called them magnum springs. try them yes but it will be a $2000.00 experiment.

 

[496 polara]

If seller can't provide trusted flow numbers for them I would pass. Aluminum heads can be had for less than that.

 

[Lefty71]

Your car already has 915 castings to start with? Whats the use, hot street??

I think 496 Polara is quite right.....unless you are dead set on a sleeper, then aluminum aftermarket would be a more economical choice.

 

[gtxrt]

Your car already has 915 castings to start with? Whats the use, hot street??

I think 496 Polara is quite right.....unless you are dead set on a sleeper, then aluminum aftermarket would be a more economical choice.

no the car has 516 heads

 

[BSB67]

I’ve lost track. 383 or 440?

IMO, if they are done right (picture are not enough to know) and flow 260-ish and going on a 440, they will help everywhere, probably a lot.

 

[PRHeads]

I’ve lost track. 383 or 440?

IMO, if they are done right (picture are not enough to know) and flow 260-ish and going on a 440, they will help everywhere, probably a lot.

While it’s certainly well within the realm of possibility that those heads could flow 260-ish, the number of home ported(or done by a shop that doesn’t specialize in porting) BBM factory iron heads I’ve had on one of my flow benches since 1993, reaching that threshold, I can count on one hand.
Most are typically in the 240’s range, especially the 915/906 heads, where you really need to get after the SSR to keep them from backing up after .450-.500 lift.

That being said, it shouldn’t be hard to improve on unported, stock valve size, 516’s.

 

[BSB67]

I figured that if my head/engine guy from 1993 working by himself in a little no name shop in the middle of nowhere could get there, most good shops should be able too.

There were a couple SS/I and H cars running out of his shop. Those guys do think a little differently.

 

[PRHeads]

You must have the numbers from the before/after tests I did on the set you sent me.

Edit-I found my notes on them…….. looks like they would be a set I’m counting on my one hand.

 

[BSB67]

Yep, but I’m going from memory (I do have everything written down, just didn’t look them up). I think your numbers were a little lower than Brent’s. But your measurements were after the heads had a lot of years and miles on them. IIRC, Brent’s flow bench only drafted 10” and we converted them to 28”.

 

[gtxrt]

That being said, it shouldn’t be hard to improve on unported, stock valve size, 516’s.

would that be keeping the 1.6 valves or going bigger

 

[PRHeads]

I was referring to replacing the 516’s with something else.

Imo, changing the exhaust valves to 1.74 on a 516 is an improvement, but it’s not going to do anything magical.

Hers an example of the “same job”, but from two sources.

906 heads, 2.08 valve, valve job and bowls blended.
One got the SSR reshaped, one did not.
Neither had any work done to the runner, pinch, or chamber.
Both heads done by Mopar knowledgeable shops with a flow bench.

Lift——-A/B
.100— 69.8/74.3
.200—139.7/153.6
.300—201.6/204.0
.400—248.7/237.5
.450—252.4/239.3
.500—256.2/240.1
.550—254.3/237.4
.600—258.0/231.8

I also had another set of 906’s here, done in a similar fashion, and I was told they had been used on a build that was featured in a magazine.
The SSR had been laid back a fair amount, but was only reworked from the bowl side, and that resulted in a fairly abrupt edge where the whittling ended.
My recollection is those didn’t break 240 either.
(Found my notes on those……peak flow of [email protected])

 

[BSB67]

I just looked them up. Pretty close at 0.30”, 0.40”, and 0.50”. 261 cfm compared to 263 cfm @ 0.500”.

To the OP - those heads, 221 @ 0.050” cam w/ 0.455” lift, 4200 lbs, 3.23 gear, 1700 rpm converter. P235-70 BFG. 12.9s @ 108-109. It drove just fine.