Hey, I'm putting my B20 back together for the hundedth time and I wondered if my jet needles are a little too conservative for what I'm doing. I just got the head ported and I'm expecting to flow a little more air at the top end. Previous torque curve with all but the head porting was enormous midrange surge that dropped off somewhat suddenly.
Stock 1969-1970 B20B bottom end
Isky street performance cam/lifters/pushrods
Cloyes timing gear set
Shaved and ported B20 head, not sure which but probably the less desirable casting
Rebuilt SU HS6's with "DX" needles, big honkin velocity stacks, stock intake
iPd 4-1 header and 2-1/4" glasspack
Stock B20B cast iron 078 distributor with vacuum retard unplugged
Do I need richer needles to support the increased head flow? Or is it not likely to be that dramatic?
I'm also curious what the ignition curve looks like from the stock distributor, and how much I have to gain from more timing.
EDIT: I have an 0231 153 003 ready to throw on, I've been told that 003 is best for performance applications short of using electronic ignition. Read up on the 078 and it's not terrible but flattens out quick.
Stock 1969-1970 B20B bottom end
Isky street performance cam/lifters/pushrods
Cloyes timing gear set
Shaved and ported B20 head, not sure which but probably the less desirable casting
Rebuilt SU HS6's with "DX" needles, big honkin velocity stacks, stock intake
iPd 4-1 header and 2-1/4" glasspack
Stock B20B cast iron 078 distributor with vacuum retard unplugged
Do I need richer needles to support the increased head flow? Or is it not likely to be that dramatic?
I'm also curious what the ignition curve looks like from the stock distributor, and how much I have to gain from more timing.
EDIT: I have an 0231 153 003 ready to throw on, I've been told that 003 is best for performance applications short of using electronic ignition. Read up on the 078 and it's not terrible but flattens out quick.
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