I just went out and purchased a carter high volume mechanical fuel pump,Part#m6900 for my 305.I noticed on the carter fuel pump there is a inlet hole and a outlet hole and that's it,While on the stock pump,There's a inlet hole and a outlet hole and also a hose running to the bottom of the fuel pump.Is this some sort of return hose,And can it be bypassed? I was also thinking of installing bigger jets in my carb (carter 600 afb),And makeing it a 650c.f.m. carb. I was thinking i should be o.k. with the bigger jets since I'm running a bigger cam,And ported and shaved heads and a ported edelbrock performer r.p.m. intake.Would this be a good move?

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82 firebird with 305H.O.,Block bored .30 over,Keith black hyperutectic flat top pistons for 10 to 1 compression,Turned crank,Magnafluxed connecting rods,Melling H.V. oil pump,and double roller timeing chain,Ported and shaved heads w/3angle valve job,Z-28springs,Summit push rods and comp cams magnum roller rockers,Ported Edelbrock performer r.p.m.intake,Carter 625 afbcarb,Accell spark plugs,wires,and H.E.I.super coil,Heavy duty cap and rotor,Clevite performance cam with 450-460 inches of lift,Comp cams lifters,700r-4 tranny rebuilt with trans-go rebuild kit,corvette servo,New torQue converter,Flowtech headers,Flowmaster muffler,3.73limited slip rear end,Energy suspension bushings from front to rear,Energy suspension tranny mount,New center link,ball joints,trans-am steering box,ASP power pully.

 

Going with bigger jets will not increase the cfm of your carb...

The small port on the side of the stock pump is a return line. You don't really need it. I think my Carter pump (if it's the same Street pump) puts out about 7psi which may be too much for a 305. I don't know about Carter style carbs as much, so it may be OK, but I think a little high...

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

if you have the same pump as me (and you probably do)the street pump is set at 6 p.s.i. I've seen a few articles on the web about built-up 305s and all of them run 650c.f.m. carbs,So i figured with as much as i've done to mine i should be safe.