I wouldn't spend the money on another carb for your 302 unless it was to get a 4053 780 for it. You might notice a slight improvement in throttle response with a smaller carb but with a vacuum secondary you can't really over carb your engine. The secondary opens based on the flow of air through the primary throttle bores. A vacuum is created in a venturi which operates the diaphram that opens the secondary throttle blades which will only open enough to feed what the engine needs.

 

I figure a good old 3310-2 Holley 750 cfm vacuum secondary carb. is fine for a 302.

May have to tune it a schosh since it should be tuned out of the box for a 375hp/396 by Holley, but never the less, it will do fine!

AND not correct by no stretch, but my original 350SS's 750 Q-Jet ran great on my old junk301 back years ago once I set the back top butterfly's to tip in like I wanted them.

pdq67

 

With a 4 speed either a 600 or 650 double pumper would be my choice (leaning toward the 600 unless its a little radical). If you want original looks then the 'ole 780 will perform almost as good as the double pumper.

 

When I had the 4053 restored on my stock '69Z, I replaced it for a couple of months with a dual-feed Holley 600 VS (#0-80145) I keep as a shop spare; much nicer for normal street driving than the 780 - crisper throttle response and better driveability, and it's exactly the same physical configuration as the 4053 - uses the same fuel lines, just had to wire up the electric choke. The only reason it had a 780 was to make it legal for SCCA Trans-Am. :thumbsup:

 

the way I read it, back in the day, they put the 780 on the 302 just to be sure they had enough cfm for racing purposes.
Edit: woops, didn't see this had already been posted ( yaay i was right! )

 

Thanks everybody, I'm kind of leaning towards a 650 for better low end perfomance for just normal street driving, I have the original 780 that I can put on for shows.

 

650 what?

 

I was thinking of a 80457S -600 CFM Holly, or a 80555C -650 CFM, also I'm concidering a 80670- 670 CFM Street Advenger.

 

Can we modify the old PN 1850 600 cfm, vacuum secondary Holley carb. into a 4150 type w/ cathedral bowls and a rear jet plate??

pdq67

 

Its been done.