['70chevy]

Anyone know if the fuel pick up tube for the BB is of a different size than for a SB? The one I've got (was SB, converting to BB) is just a 64th" less than 3/8. I'd appreciate any info on this!
Thanks!

 

[Carl Brune]

You're talking about the pickup in the tank right? There are two sizes, 5/16" and 3/8". In 65 at least 4-bbl carbs got 3/8, the rest got 5/16, for all lines from the gas tank to the carb, including the tank pickup. So you probably have a 5/16 pickup. What size is the long line which runs to fuel pump? --- Carl

 

['70chevy]

Hey Carl,

Thanks for the response. Mine looks too big to be 5/16" but just a shade under 3/8". Is the size i.d. or o.d. of the line? As I said initially, mine is just a fraction smaller than 3/8" o.d., I'm talking less than 1/64" smaller. But again that's the o.d. The original line is gone, and I don't know what size it had. The vent is definitely 3/8", but with the corrosion it's kind of hard to tell what the original was on the pickup.

 

[Carl Brune]

The size specifies the o.d. of the steel tube. Of course for rubber fuel hose the size gives the right i.d. to fit snug over a steel tube. I happen to have my old 5/16" tank unit handy. On nice clean straight sections of the tube I measure the o.d. to be about 5/16+0.004" so it is pretty close to 5/16. Also some cars (later than 65) had more lines, like a fuel return line. Hope this helps. --- Carl