351w Help

[dana deamann]

im putting 1975 date stamped heads on the new motor. completely gone thru with fresh valve job. im looking for rockers and i can not find any stock rockers for a 5/16 stud. every aftermarket rocker is either 3/8 or 7/16. and no old stock parts... anyone else ran into this?

second question is about the harmonic balancer. i bought a new one and installed it. the motor is at top dead center but the TDC mark for the balancer is at about 1-2 oclock. it should be at about 11 o clock. i know they had a few different spots for the TDC pointer throughout the years and this balancer is supposed to be for 1969-1985 351w's. what im wondering is if the balancer is weighed to be in a specific position on the crank? im not so concerned with the timing marks. ive made my own.

 

[jozsefsz]

Stock rockers are stamped sheet metal pedestal mount rockers, typically using a bolt and not a stud. Stud-mounted rockers you're only going to find in 3/8 or 7/16 (did they ever make them in 5/16?). I'm gathering you're trying to update to a roller rocker. You can either get a pedestal mount roller or there are screw-in studs available that will take your 5/16 and make it 3/8 for stud mount.

Your original balancer and a 351 balancer should both be 28 oz. so I imagine if it's dimensionally correct it should work fine. Your probably best off comparing it to the original or to the correct part number to see if they're marked identically. I personally have no idea, perhaps someone else will.