mrh12000

i am having dickens trying to figure out the belt and pulley arrangement for 396 with PS. The alternator mount bracket puts the alternator pulley 3 grooves out from the block on the crank pulley,past the outer groove on the two groove water pump pulley (the PS pump uses the second and third groove on the crankpulley). Unfortunately my AIM does not cover the 396, and the 65 factory manual 396 supplement does not show it. Corvette suppliers only list two groove water pump pulley, not a 3 groove, can anyone advise?
also, what about the inner grooves on the crank and water pump, is there a belt? is it tight no idler or anything/

midyearvette

i can't speak for the 65 bb cars but my 66 bb uses two groove pulleys on the balancer, water pump and power steering pump
the alternator is driven with a short belt from the steering pump and the inner groove on the water pump is fitted with a short belt from the balancer and there is no adjustment on that belt, the outer groove on the balancer drives the ps pump
dunno if the 65 is the same or not......hope this helps....

mrh12000

never thought of that, makes sense, thanks. my 3 groove crank pulley is aftermarket maybe expains why thinking need to use that outer groove.

JohnZ

There were no 3-groove pulleys on the '65 396; the crank, water pump, and power steering pump all had 2-groove pulleys. The rear groove on the crank and water pump used a captive belt with no idler, the forward groove belt drove the crank, water pump, and rear groove of the power steering pump, and the forward groove of the power steering pump drove the alternator pulley.

Your '65 Assembly Manual shows this L-78 arrangement (and all the parts) in section N40, sheet 7, and in View "A" on that sheet.

midyearvette

all these correct pulleys are available from vendors but pricey!
the two groove ps pump pulley is around 150.00 alone i think.....