470 or 670 carb for a v8 302

[panamacj5]

Hey...i need to buy my carb and ive read in differente posts different opinions i was wondering which one will be better for my ford 302? they guy who is building the engine says the 670 will the best choice after he tunes it a little bit...i will apreciate if someone can educate me on this please

 

[mtnwhlr]

The 670 is good for a 302 in a Jeep. I think any bigger and it will just hurt your gas mileage.

 

[Old Dog]

I'd go 470, here's Holley's site to figure it out. Holley Interactive Carburetor Selector
I ran a 670 on my 350, I had to rejet it smaller and it was still to much.

 

[coldair]

I've ran a 600 cfm on my ford 302 in my 74 CJ5 it loads up when crawling around. I've rejetted it and messed around with it a TON! It is to big for using for a rock crawler. Bought a 500 cfm cured it. You just don't get enough velocity through the carb with a 600 cfm around 2000 or lower to make it work right. So go with the 470 cfm and don't look back.

 

[coldair]

I should have asked what your doing with your jeep? What's been done to the motor? I gained 2 mpg with the 500 cfm because it works better at atomizing the fuel at lower rpms. I still only get 12 to 13 mpg with it though.

 

[panamacj5]

thanks for the replys...down here we have tons of mud and huge hills...hardly any rock crawling, it will have d60/14bolt with 40's
should i go with the 470

 

[derf]

If you're building the 302 for higher RPM in the mud, go with the 670 and match it with a good intake and cam.

If you're building not much more than low RPM torque, the 470 is the one you want, again with the right intake and cam.

 

[panamacj5]

everything will be stock except for the camshaft and intake manifold basic operation range starting at 1500 rpm and a msd distributor without box...my top rpm 4 wheeling will not go over 4500...so will the 470 truck avenger be the best for my rig ?
thanks for all your inputs

 

[Incommando]

IMHO Holleys suck off road unless it is highly modified or the T/A version.

A 470 would give you better all-around performance. The #1 mistake that people make, be it on a street car, drag car, or jeep, is they put way too much carb on the engine. The 470 is a poplar choice with the FSJ crowd and that is on 360 cid engines.

 

[coldair]

IMHO Holleys suck off road unless it is highly modified or the T/A version.

A 470 would give you better all-around performance. The #1 mistake that people make, be it on a street car, drag car, or jeep, is they put way too much carb on the engine. The 470 is a poplar choice with the FSJ crowd and that is on 360 cid engines.

X2 I argee with Incommando the reason why my 302 had a 600 on it the PO installed it. At the time didn't want to spend the money to buy a diffrent one. Go with the 470.

 

[Niedhogg]

IMHO Holleys suck off road unless it is highly modified or the T/A version.

A 470 would give you better all-around performance. The #1 mistake that people make, be it on a street car, drag car, or jeep, is they put way too much carb on the engine. The 470 is a poplar choice with the FSJ crowd and that is on 360 cid engines.

I agree, I have the 470 T/A on my AMC 304 , without a cam, and it's seems a bit too big. I've already had overfueling problems with it, but I have been tuning it and it's been improving with everything I do. A mild cam is exactly what my engine needs with the 470. I wouldn't go any bigger than the 470, and make sure that you buy the T/A version and you won't be dissapointed. The 302 fords have way better head flow than the AMC 304s do.. it would be a good combo.

 

[panamacj5]

Ok thanks everybody for their input ...i think i will go with the 470 truck avenger ...but before let me add that i have read in several posts and in holley's webpage that the 470 is not recommended in v8 engines ...any knows anything about this ?

 

[derf]

Ok thanks everybody for their input ...i think i will go with the 470 truck avenger ...but before let me add that i have read in several posts and in holley's webpage that the 470 is not recommended in v8 engines ...any knows anything about this ?

It's marketing . Feel free to ignore that. 470 CFM is fine for a AMC 304 with a stock cam.

If you're running a race cam with solid lifters and a big open single plane intake, and you're pushing 7K RPM, you could use a 670. But you're not so go with the 470.