Potential wise I don't think they're really that far apart. What you can't get w/ the D0OE's is the P's better combustion chamber. How much that helps I can't say.

 

Do you really think the combustion chamber is that much better?

I've seen flow numbers on the D0OE heads that have them flowing as well as the edelbrock performer heads. That was after porting and bigger valves. Of course the edelbrock heads were box stock though.

The home ported 351 heads with 1.94 intake and 1.60 exhaust flowed:

lift .100 .200 .300 .400 .500 .600
Int 57 114 165 198 211 211
Exh 47 93 132 162 177 181

I'd like to see some flow numbers in "P" heads that were similarly prepped for comparison.

I guess many would ask why I don't just buy aftermarket aluminum... Because I already have these heads and the associated springs, locks, retainers rocker arms. Now that I have my 351 heads off the car I was thinking of hand porting them and sticking bigger valves in.

 

The D0s are basically the GT40 head (Ford created the GT40 from the original D0OEs) and everyone knows the Ps outperform the GT40s.

I agree if your class doesnt require factory iron heads the aftermarket alums are worlds ahead of the irons from Ford.


Real world expierence. Had D0s race ported and with tuning ran a best ever with them at 6.98@97 in 1/8th.
With absolutely no other changes other than Stage2 Canfields ran 6.47@103. That is a serious difference fellows.
The D0s are good for what they are but give up alot of power.
Later this car was treated to Stage 3 porting and ran best of 6.34@106 before I sold it.

The Canfields had the same 1.94 /1.6 Chevy valves in them as the D0s did.

 

My fully ported D0's with 1.94/1.6" rev valves
http://www.mustangcentral.net/mat/351/

If you have the heads, use them! Those came on my '70 351w which I picked up for $100

The only thing I really don't like about these heads, exhaust seats suck and the damn sparkplugs don't come in as many heat ranges

btw p's will flow roughly the same with a smaller port, but the d0's have a little bit more peak flow potential...not that it matters

 

tateg......I know for a fact the P's chambers are a better design. That was half the reason they did them. They have a very effecient chamber. Max power typically comes w/ total timing in the very low 30s.

I've seen flow numbers from smart porting that better the numbers you posted and they were w/ 1.85/1.54 and 1.85/1.46 valve combos. (exhaust was a tad under but intake better).