what size carb should i go with

[fordman]

what kind of carb should i but on my 302 bored out to a 308 what would be a specific size someone told me a 650 would be too littel anyone one know what i should go with engine was fuel injected wires are all cut up so im carburating it any info would be great thanks

[mustangboy]

650 would be perfect for that size engine. Only reason to go bigger is if it was a high winding drag only engine that does nothing but wide open throttle driving. Trust me a 650 is not too small. Put it this way I'm only using a 750 on my 429. The smaller carb will give you much better street ability than going to a 750.

[JASON408]

650 would not be to small if any thing maybe to big .i would put a 650 on it ran one on my brothers 302 and it ran great i have everything to switch over to carb if your intrested a dissy a performer rpm intake and a holley 650 dp holley blue and reg

[85_SS_302_Coupe]

Personally if i buy another carb for a 302ish cubic inch engine it'll be a 600 double pumper. I've been running a 650dp for a couple years but i had planned on using it on a 351W that i never got...it runs great up top but it's a little soft on the bottom end. Unless you've got some nasty heads and cam on your 308 (like some 2 inch intake valves and a .550+ lift cam) then the 600 will flow plenty enough up top and will be nice and crisp on the bottom end.

If i remember right your car has GT40 heads right? My buddy ran the same heads with a Stealth intake and a really wore out and tired 600 vacuum secondary carb (piece of crap) and was running 13.40s blowing the tires to pieces. If he had a decent cam and some traction he would've been all over 12.90-80s.

[fordman]

see as u seen my car ss302 u see my set up i got the 650 holly on it was nice after the build and i had the car on the road but after id say a month the car started hesitating to pull up a hill and boggs out like its falling on it face im shore it seems like its starving for fuel unless the carb is messed up but this 650 holly is like brand new i dono whats up with it im confused. any info would be good someone told me i need ta throw a 750 on there witch i doubted.

[85_SS_302_Coupe]

Think about it...if it ran good when you first got it running and now it doesn't, then the size you have on it works....something is wrong with either the carb or your fuel pump if you think it's starving for fuel. It sucks but just because the carb is new doesn't mean it can't be screwed up. Do you know anyone else with a carb laying around that you might be able to swap out and see how it runs? That would let you see if it's really the carb...and if it is you can go from there to see what it needs to get running right again. If it still runs rough with another carb then it's not the original carb and you need to look into something else.

[fordman]

there is a littel diagraph on the carb that says holly on it when i spray fluid around the carb it seems to idle up an down ike theres a leak somewhere iv jus descovered this where could the leak be at around that circule thing

[85_SS_302_Coupe]

Well where exactly are you spraying it? If you're spraying around where it can get sucked into the carb throat, and it's something that'll burn, then yeah your idle will rise a little.

[fordman]

no i sprayed it in the diagraph thing

[theyallslow]

cubic displacement divided by 2 (ex: 351=175.5)

maximum rpm divided by 1728 (ex: 6000 rpm=3.47)

multiply those two figuires (ex: 175.5 x 3.47=608.98 cfm)

[03blwn281]

cubic displacement divided by 2 (ex: 351=175.5)

maximum rpm divided by 1728 (ex: 6000 rpm=3.47)

multiply those two figuires (ex: 175.5 x 3.47=608.98 cfm)

Absolutley CORRECT....
Go with the 650!!!!