351w heads 302 block

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Mar 25, 2008 | 09:31 PM

Kothlow

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351w heads 302 block

Is there much of a power gain? i have read you have to drill and tap the block for larger Dia head bolts, just wondering if its really worth the work?

Mar 25, 2008 | 10:07 PM

Conanski

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Both motors use the same head casting, and with anything after 1977 the only difference between a 302 and 351 head is the size of the bolt holes, 7/16" on the 302 and 1/2" on the 351. All you need to bolt 351 heads on a 302 is spacers for the 7/16" bolts, no drilling and tapping necessary, but unless you use a pre '77 351 head there's absolutely no gain.

Mar 26, 2008 | 10:58 AM

Kothlow

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More than likely I wont bother. I had heard they flowed a bit better, but wasnt sure. Thought I could get away with a cheap little boost in power

Mar 26, 2008 | 12:47 PM

Conanski

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Quote:

Originally Posted by Kothlow

I had heard they flowed a bit better, but wasnt sure. Thought I could get away with a cheap little boost in power

It's true you can gain some power, but it depends what motor you are starting with and what heads you would go to. What year is the motor?

In the category of cheap upgrades for more power a cam change or stepping up to 1.7 rockers is right at the top of the list.. above changing heads actually.