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Boss 302 Heads vs Cleveland 4V heads

G Guest
Hello Fellow Enthusiasts; Here's a "strange but true story"....I found out the other day the "Cleveland" heads I spent HUGE $$$$$ on ( $3,000.00) the BEST of everything!!!...titanium intake valves, retainers, keepers, stainless exhausts, 3 angle valve job, bronze guides, ported & polished & bench flowed, dual springs...all work done by a Winning Winston Cup engine builder in Colorado...are in fact....wait for it...Boss 302 heads as confirmed by the casting #s DOZE 6090A. Soooo, do I sell the heads & attempt to recoup my $$$$, or use the 302 heads?....What changes/alterations?, would be necessary to make the 302 heads work on a Cleveland block. I have a Blue Thunder manifold & 180 headers. When placed side by side to a Cleveland 4 V head the differences are very noticeable...Must state...the Boss 302 head is PRETTY!!!....THANKS!!!...Mark
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bosswrenchbosswrenchMember
Keep them. There's practically no difference beween Boss 302 and Boss 351 heads except for a water passage used in the 302 block and not used in the 351C block. Minor machining of the squarish water passage in one corner to round followed by a brass freeze plug of suitable size was the factory's method of interchanging the castings.
panteradougpanteradougMember
As far as I know, the significant difference between the Boss 302 and the Cleveland is the water passage in the head.

The Cleveland has it blocked in the casting. I think all you need to do is fabricate a plug to sit in each head to block the 302 water passage.

You probably will need a machine shop to do that for you since the plug is what will need to be machined and the water passage will need to bemachined round and countersunk to accept the plug.
panteradougpanteradougMember
quote:
Originally posted by 1Rocketship:
Is there not also a water passage difference that enters the intake manifold, or is this the "water passage" you are referencing?....Mark


No on the intake. It will bolt up no problem to the heads.

Difference is simply the water port in the heads.

George makes a good point though, the combustion chambers in the Boss 302 head are a little smaller.

If you have the dished pistons, this would be an extra plus for you to use them.
R 1Rocketship (Guest)
quote:
Originally posted by Cowboy from Hell:
The combustion chambers are smaller too

Nominal chamber volumes

1970 Boss 302 = 58cc
1970 351C 4V = 63cc
1971 351C 4V = 66cc

In my opinion it would be a shame to bugger up the Boss 302 heads by adapting them to the 351C. Cleveland parts are a dwindling resource, Boss 302 parts are even moreso.

-G
Hello George; I was thinking the same thing in regards to "Buggering Up" the Boss 302 heads. Might be difficult to recoup my initial $3,000.00 cost....Any takers?!.....Mark
George PGeorge PAdmin.
I see NOS Boss 302 heads, bare Boss 302 castings, even used Boss 302 heads advertised for $2000 or more on eBay frequently. List them on eBay for $3000 buy it now. With porting and the good valves my gut feeling is your Boss 302 heads will sell easily. Especially after everyone gets their tax returns in the mail. Make sure to include some pictures detailing the work that's been done.

If my financial situation were better I'd buy them at that price. I'd want to see the porting work before I bought them however, because I'm leery of guys porting the 4V Cleveland heads. This is why I mentioned including pictures of the work in your eBay auction.

(I'm an enthusiast of the Boss 302 motor)

-G
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