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Started this for sixt9coug as I did this one time.

You need stepped head bolts which I believe are obsolete.
Or use hardenend Flat washers under the stock head bolts.

The biggest differance in the 351 and 302 head is the valve sizes. The 351 has 1.84 intakes and 1.54 exhausts vs 1.78 intakes and 1.46 exhaust. Some of the 260 and early 289 had even smaller valves.You also loose about 1/2 point of compression. And the intake port is slighty larger on the 351.

Also after about 1975 or 76 the 351 and 302 use the same 302 head.

The best are the 1969 for port flow.

IMHO just bolting on a set of 351 heads are a waste of time unless you put more cam and carb on the engine with some head work. A removal of the exaust thermactor bump, a multi angle valve job and a bowl blend work real well.
 

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cool cool. i just have 2 pairs in the garage. i usually snag them when i see them at the yards. good info to know thanks man.
 

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The shouldered 1/2" to 7/16" head bolts are still available. Also the 70 heads are the same as 69. mm
 

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You can make up some of the compression loss with milling the heads down... I do believe there are some water passages that have to be drilled out... We spent a lot of time talking about this topic on another thread... I can't remember what it was called... Maybe Logan or ModifiedMark remember.

The long and short of it is... you CAN do lots of things with the 351W heads on a 302, but you are money ahead to buy a set of World Products' Rousch 185's or something.

Ron.
 

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I will have to agree with Ron. When I had to make a desision on what to do with my heads I came to this conclusion.

Rebuilt stock unported heads converted to adjustable valve train $650.00
Rousch Cast Iron Heads- $799
Edelbrock Perfomer RPM Heads $1000.00

I figured that It wasn't worth the money to mess with the factory castings. I opted for the Edelbrock Perfomer RPM's. Haven't got the motor back in the car yet to test them out though. I can't wait!!!!!!!

Kevin
 
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