351heads on 302

M

mikey1

Forum Member
i have ported 351w heads for my 302 jw if i need 351 specific head bolts also if i need 351w specific pushrods

whats the same whats different ?
 
302 head bolts w/ taper for 351 or studs w/ T- washers
push rods all depends on your set up , 1:6,1:7s, installed hight (springs) ect.......
 
Last edited:
mikey1 said:
ive got 1.6 roller rockers
Click to expand...


Telling us what rocker ratio you have is not enough. Valvetrain geometry is something that MUST be checked on every engine as there are variations in the deck height, valve length, head deck, etc., that all contribute to the end result of pushrod length. As for the diameter, that depends on the amount of spring pressure and RPM you plan on turning. For example, a 7000 RPM engine with springs having 220# of seat pressure, you could get away with a 5/16 diameter pushrod. Now if you plan on running the same RPM but are using springs that have near 300# of seat pressure, a 3/8" diameter pushrod would be needed. As you increase RPM, the valve train becomes more and more unstable, and this will also require an increase in diameter. This is also important to take full advantage of the cam lift. Using too small of a diameter pushrod will cause excessive deflection resulting in decreased lift and HP.
 
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