Ford 302 SS build

[Jim Caughlin]

Originally Posted by fordteacherguy

The 68 302 iron head HP dropped to 207 hp and could be a great combo. 23 HP less than aluminum!

Which carb comes on that combo?

[Doug Hoven]

Originally Posted by Jim Caughlin

Which carb comes on that combo?

Depends on whether you call it a Ford or a Mercury 302. If run as a ford, it gets the 450cfm version of the motorcraft 4300 spread bore, air valve secondary carb. If called a Mercury, you are allowed to run a 600cfm 4150 holley.

[ShipC1970]

Originally Posted by Doug Hoven

Depends on whether you call it a Ford or a Mercury 302. If run as a ford, it gets the 450cfm version of the motorcraft 4300 spread bore, air valve secondary carb. If called a Mercury, you are allowed to run a 600cfm 4150 holley.

Why is that and how is that? So I have the original 70 block and matching heads. So hypothetically even though it’s from a ford mustang and I run it in my mustang in GT/QA or PA and say it’s a “mercury” engine I could run a 4150? Who checks this by the way? Forgive me for all the questions I’m new!

[Jim Caughlin]

Originally Posted by ShipC1970

Why is that and how is that? So I have the original 70 block and matching heads. So hypothetically even though it’s from a ford mustang and I run it in my mustang in GT/QA or PA and say it’s a “mercury” engine I could run a 4150? Who checks this by the way? Forgive me for all the questions I’m new!

You can run GT only if the comb is a hybrid. If the combo can legally be run in SS, you can't run GT. In my case, I am building a '64 Comet with the 289/210 combo. If I run the large Autolite Merc combo, it is a SS/MA. If I run the small Autolite Ford combo, it is a GT/QA. You can't swap between classes, the argument for this rule was that people were running GT with legal SS combos to avoid a potentially losing heads up runs.

[ShipC1970]

Originally Posted by Jim Caughlin

You can run GT only if the comb is a hybrid. If the combo can legally be run in SS, you can't run GT. In my case, I am building a '64 Comet with the 289/210 combo. If I run the large Autolite Merc combo, it is a SS/MA. If I run the small Autolite Ford combo, it is a GT/QA. You can't swap between classes, the argument for this rule was that people were running GT with legal SS combos to avoid a potentially losing heads up runs.

So I have a 89 roller 302 in the garage. If I run that block with a set of 68 302 heads I could run it in GT because it would be a hybrid? And I could claim it as the merc 68 302/220 combo with the 4150?

[1347]

Originally Posted by ShipC1970

So I have a 89 roller 302 in the garage. If I run that block with a set of 68 302 heads I could run it in GT because it would be a hybrid? And I could claim it as the merc 68 302/220 combo with the 4150?

Yes, you could use the piston that fits the 68 302 combo ( 4 valve reliefs), the 68 4V heads ( C80E-F) or the aluminum replacement head, which is the better head, and more cost effective. And as a Mercury that combo takes the Holley 600cfm 4150 carb.
The 390, 428, 351c, even 351w are good combos to research also. I dont think the 2bbl 302 is good for Super Stock, Matt Hawk has played with the 302 2bbl and the carb is just too small for the hp rating.

[goinbroke2]

Originally Posted by 1347

even 351w are good combos to research also.

What 351w would be able to make any power? Even the rare D0 heads flow same/less than gt40P's. They barely support a 302 let alone 351 inches.

Reminds me when Ernie Elliot built a 327" for restrictor races and qualified WAY WAY quicker, so nascar made the "minimum cu in" ruling.

What secret am I missing where a top end that is barely enough to feed 300 cubes will run in a performance category with 50 more cubes?

Edit: On Stan's site I checked out the basic heads from ford/chev/dodge.

Mopar 051 head 1.88/1.60 (no idea if its good or bad)
50/49 113/97 165/123 188/123 193/137

Chev 462 1.94/1.50 (again no idea if this is a good head or not)
50/54 119/88 167/116 198/128 212/134

Ford E7 (as good as any and better than most stock ford heads) 1.78/1.45
52/39 95/74 132/98 143/104 159/109

To me, ford heads barely flow enough for 302's and once you see what 360's and 350's have for "base" heads, the 351W to me is way under headed.
Richard Holdener ran a stock junkyard 302 and got 259hp and a stock 351 got the same but at a lower rpm which to me says as cast, stock heads will flow enough to produce 260hp and that's it. (for a base to start from)

Am I reading something wrong??

[Dwight Southerland]

Originally Posted by ShipC1970

So I have a 89 roller 302 in the garage. If I run that block with a set of 68 302 heads I could run it in GT because it would be a hybrid? And I could claim it as the merc 68 302/220 combo with the 4150?

Mixing engine components does not make a hybrid. Using an engine by the same manufacturer that was not offered in your make-body is a hybrid.

[ShipC1970]

Originally Posted by Dwight Southerland

Mixing engine components does not make a hybrid. Using an engine by the same manufacturer that was not offered in your make-body is a hybrid.

Gotcha so if I run a 390 combo I could run in GT since the 390 wasn’t offered in the 70 mustang? What about a 68 302 then? I couldn’t run it in GT since the 302 was offered in the 70 mustang?

[Doug Hoven]

Originally Posted by ShipC1970

Why is that and how is that? So I have the original 70 block and matching heads. So hypothetically even though it’s from a ford mustang and I run it in my mustang in GT/QA or PA and say it’s a “mercury” engine I could run a 4150? Who checks this by the way? Forgive me for all the questions I’m new!

No worries, it's confusing to everyone. In "GT" you are allowed to run any engine combination from the "family." For example a 283 in a 4th gen F body, or a pontiac/olds/buick 455 in a camaro. To run a 68 302, you could use your block, but you'd have to find a set of heads for the 68 4bbl engine. Whether it's true or not, the paperwork exists that a Mercury 302 in 1968 was available with a Holley, whereas the Ford cars had the 4300 autolite. So, long story short, to answer your question, yes. You could run a 1968 4bbl 302 with a 4150 in your 1970 mustang in GT/QA or GT/PA.