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I have a few questions for anyone running early 351W heads on their 289/302 blocks.

Can the heads be milled to acheive a 54.5cc combustion chamber without having to mill the intake manifold to seal?

Excluding the bolt size difference, what are the external difference to the heads. Are the accessory holes and freeeze pluys in the same location? Are the exhaust ports in the same location (i.e. can swap without reconfiguring exhaust existing system ?

How do the stock 1.84/1.54 valves flow compared to upgrading to 1.94/1.6 or 1.94/1.54 ?
Do the heads need just cleaning in the ports, or work better with more radical port massaging?

Contemplating running these heads on a 331 stroker (not a option to run the 351 block). Any other tips or pro's & con's ?
 

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I can't answer your questions Dino...but regarding pros and cons, it would seem that by the time you pay for all the machine work (and I'm pretty sure that means working on the intake too) you'll have as much or more in the heads as a good set of aftermarket heads. Speaking of which, AFR 185's would be perfect for your stroker application. BTW...based on your question, I get the feeling you are contemplating stroking a 289. I've read this isn't recommended because of the differences in the skirt at the bottom of the cylinder bore. Better double check me on that, though.

Phil
 

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Bob, I have a real good article on 351W heads. Basically all 31W from 69 to 76 have the same potential. The article shows some intersting stuff this company does with the bump in the exhaust port, by making it into a fin to improve low end torque without hurting upper end.

Unfortunately, my scanner took a dump, I'll make a copy.......maybe I'll drop it off next Wednesday night at the cruise! Now that scouts are down for the summer!
 

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Discussion Starter #4
Unfornuately, I can't upgrade to a aftermarket head. The club I run opentracks is one of the few that still actually runs timetrails (you are technically in a timed competitive event). An aftermarket head is too easy to notice in tech. A stock head (even a 351) will probably pass tech. Technically a stroked 331 with 351 w heads isn't legal, but since most of the competition is late model, they have been giving the old lead sleds a little more leeyway instead of dropping us down in classes.

Thanks , Bob.
 

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Can the heads be milled to acheive a 54.5cc combustion chamber without having to mill the intake manifold to seal?

Possible but not recommended IMO...the chamber design would require substantial milling, which would affect alignment as well as deck stablility. Better to use a domed piston or flattop, depending on application. As this is going to be a stroker, quantify and compute the CR with a stock W head and the requisite stroker piston before considering modifications.

Excluding the bolt size difference, what are the external difference to the heads. Are the accessory holes and freeeze pluys in the same location? Are the exhaust ports in the same location (i.e. can swap without reconfiguring exhaust existing system ?

Can't personally comment on accessory holes but they appear similar to 289 heads (I've got both cores in the shop). Exhuast ports are same.

How do the stock 1.84/1.54 valves flow compared to upgrading to 1.94/1.6 or 1.94/1.54 ? Do the heads need just cleaning in the ports, or work better with more radical port massaging?

I recommend 1.9 and 1.6 valve sizes...porting is mainly confined to exhaust side and valve bowls/short side radiuses, with some attention paid to streamlining guide bosses. Consult a porting guide for more details.

All in all, great iron heads....ran low 11's with them on a 289 in the race car back in the early 80's...

Only con I can think off is lack of material available for radical porting...things can get thin in the exhaust port and bowls, especially when larger valves are used.

Good luck!
 

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Have you run a set with 1.9/1.54 valves.

Personally, no...back when I ran iron heads, the only valves available in the aftermarket were for Chevy's, so I ran 1.94 intakes cut down to 1.9 and 1.625 exhausts cut down to 1.6. This was an outgrowth of my 289 head development program, as the stock Chevy valves appeared to shroud the combustion chamber too much in the early heads.

As we're only talking about 1/16" here, I would opine very little difference to be seen flow-wise. The important area is the seat entrance and bowl area, where the round valve hole transitions to the exhuast port.

BTW, although the chamber is slightly different, I've had good luck with the 2.02/1.625" Edelbrocks on the race car...I was very impressed with their performance in unported condition (ran them right out of the box)....I know you can't run alloy heads but just wanted to reassure you that the nuances of valve size are just one minor part of the equation...

Settle on a valve size, which you think is best and most cost-effective, have the heads done, CC them, compute the rest of the dimensions for the combo, and decide which piston will give you the CR you desire. IMO, it's better to get a domed piston and cut it down (provided the dome is solid) to the CC parameter which meets your project goals.

Since you've moved squarely into the aftermarket with the stroker and appear to have the budget to build it, get what you want, whether it is supplied by the stroker builder or purchased seperately from multiple vendors.

Good luck!
 

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Excluding the bolt size difference, what are the external difference to the heads. Are the accessory holes and freeeze pluys in the same location? Are the exhaust ports in the same location (i.e. can swap without reconfiguring exhaust existing system ?

No difference at all. I have '69 351W heads on my 289. If you don't pull a valve cover off, you'd never know the difference.

I did what Pat suggested. I did not mill my heads, but instead went with 10:1 flat tops to keep the compression up to where I wanted it.

I have found no cons ... only pros. I also disagree with others that say the machine work would put you into the cost of aftermarket heads.

Here's a hint on the head bolts: I found the cheapest solution that was acceptable to my standards was to use the Trick Flow bushings and then ARP stock head bolts. That put me with good quality head bolts and about $30 cheaper than the cheapest 351 to 289 "specialty bolts".
 
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