302 w/ 351 heads
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Senior User
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From: St. Louis, Missouri
302 w/ 351 heads
I have a '65 302 that I'm pulling the heads off of this weekend because of a suspected blown head gasket. As long as I'm pulling them...what's the deal about running 351 heads on 302's? Modifieds, Clevelands or Windsors? What's the advantage over 302 heads? Will i need to do other mods? I don't expect to find any problems with my 302 heads, but I have family in the salvage yard and the machine shop business so the opportunity to get a pair of 351's is there.
Any thoughts?
By the way...the blown gasket wasn't do to heat. Low compression on #3 and 4.
Any thoughts?
By the way...the blown gasket wasn't do to heat. Low compression on #3 and 4.
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Joined: Apr 2003
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From: Fayetteville,AR
302 w/ 351 heads
the 351W is basically a stroked 302. that is why the 351 is taller and wider at the top.
so to your question... the 302 boss was basically a 302 with 4bbl cleveland heads (bigger valves). so to get a 302 boss put the cleveland heads on her. however, i do recall the need for different sized head bolts to do this. also the intake bolts won't line up with the stock intake since the intake bolt holes drilled into the head are on a different plane. i have slotted intake holes before with marginal success.
if you are still convinced that this is worth the effort...use the 351c 2bbl heads. the 4bbl heads flow way to much and you have to run a radical cam and move your torque curve up in the rpm range
if anyone out there has any other ideas let me know. just trying to help.
so to your question... the 302 boss was basically a 302 with 4bbl cleveland heads (bigger valves). so to get a 302 boss put the cleveland heads on her. however, i do recall the need for different sized head bolts to do this. also the intake bolts won't line up with the stock intake since the intake bolt holes drilled into the head are on a different plane. i have slotted intake holes before with marginal success.
if you are still convinced that this is worth the effort...use the 351c 2bbl heads. the 4bbl heads flow way to much and you have to run a radical cam and move your torque curve up in the rpm range
if anyone out there has any other ideas let me know. just trying to help.
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Joined: Feb 2003
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From: Raleigh, NC
302 w/ 351 heads
I wouldn't even consider putting Cleveland style heads on a smallblock. That was a good upgrade years ago before the market was flooded with great flowing aftermarket heads.
The Cleveland heads require a special intake manifold and pistons and also require machine work to line up water passages. No thanks!
The early factory351W heads('69 and '70) had larger valves and ports and work well on a mild 302. Later years had bigger combustion chambers (low compression) and I think in the late seventies or early eighties the 351W heads had the same small valves and ports as the 302.
There are so many aftermarket heads and even the GT-40p heads from Ford are such an improvement over the early factory heads that it's almost not worth the trouble and cost to find, rebuild and port the old heads.
The Cleveland heads require a special intake manifold and pistons and also require machine work to line up water passages. No thanks!
The early factory351W heads('69 and '70) had larger valves and ports and work well on a mild 302. Later years had bigger combustion chambers (low compression) and I think in the late seventies or early eighties the 351W heads had the same small valves and ports as the 302.
There are so many aftermarket heads and even the GT-40p heads from Ford are such an improvement over the early factory heads that it's almost not worth the trouble and cost to find, rebuild and port the old heads.
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From: St. Louis, Missouri
302 w/ 351 heads
Thanks for the feedback, y'all. I decided to stick with the 302 heads. They were supposed to be done today, but guess what...they won't be back from the machine shop 'til monday. Oh well...
Thanks again for the tips.
By the way...it's a 289
Thanks again for the tips.
By the way...it's a 289
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From: airdrie canada
302 w/ 351 heads
Originally posted by SawZall
if you are going for the "best" stock 351W heads... the 1969-74 models are the best. After 74 the chambers are opened up.
if you are going for the "best" stock 351W heads... the 1969-74 models are the best. After 74 the chambers are opened up.
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rsalter66
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