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.

[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.

[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.

[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?

[Glenn Briglio]

Originally Posted by ShipC1970

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?

Different year engine combo can run in GT.