pl8fixr

Wasn't sure if this is the right spot for this topicbut will give it a try. I have a short deck 351W that I am building for a 65 Mustang Coupe Sleeper. It is a 1969-70 era block that cleaned up nicely at .040. I am trying to get to about 10.25:1 comp.. I have the original W heads with stock valving which are supposed to be 60cc. I recently came intoownership of some newKB 151 aluminum pistons for a great price, but they will run my comp. up to about 10.8:1. I am considering a head with 64cc chambers instead. I know I might be going about it a bit backwards, but I have the flexibility to cam and carb this based on the pistons, CR, and heads. I just want to take advantage of the overbore and the cubes it provides with 1.94 or 2.02 valving. Want to go w/and iron head.

I read a few posts on the World Products Windsor JR. and Sr's. We are not going to race this at the strip, but don't want to be a dogat thestop signeither. Also, I am not committed on gear ratio yet, but will be running a C6 tranny. Anyone with any experience with a similar set up? Can I run pump gas at 10.8:1 with the 60cc heads?

KBunny

I don't really have an answer for you but I would be willing to relieve you of the 351W heads if you went with 64cc heads.

my77stang

i dont have the numbers in front of me - but i had figures before..... basically going up 4cc's isnt gonna drop it very much on a 351

you *may* be able to find a head gasket with a thicker crush which would help lower the compression a bit - but i believe you will be ok. (those heads flow nice with just a little massaging btw - stock those motors were 290 HP if i remember correctly)

69mach1377

10.8 sounds high with iron heads, but what really matters is cylinder pressure. With the right cam, they can work okay, but it might be a bit lumpy for the street.

my77stang

premium pump gas and you'll be ok - even if you had to take out a degree or two of timing you'd be fine. i mean, even with my motor at around 12:1 i can drive easy on the car with 93 octane, but it will ping if i floor it. (which is why i blend with 100 or 110 go-fast gas

Colorado_Mustang

I'm running 12+ with my 390 and can get around with 91 octane and 5 degrees lower timing. 11.5 can run about 2-3 degrees lower on 91 with my 302. Both are factory iron heads.

pl8fixr

Thanks all for the info. I might just port/polish the stockers and see what they do. Anybody know if those stock heads can be ground to accept bigger valving without complications?

scott_m_mil

You can grind them to accept a stock chevy valve, but I can't remember the exact numbers. If I recall the chevy vavles have a slightly higher valve stem that you can shorten.

my77stang

1.94 / 1.54 are good numbers, the heads can easily be machined to accpet them. most valve companies make these sizes in a proper length for a ford head.

gothand

For a point of reference, I had ported and polished '69 351W heads with 1.94/1.60 valves on a 302 with Comp Cams 270 and an Edelbrock Performer manifold, JBA headers and Holley 600 carb that dyno'd 225 hp at the rear wheels. FWIW, I believe the compression ratio was about 10:1 and I needed to run 91 octane in it.