My friend's parents just bought him a 68 mustang with a 302. It has a 2bbl carb and he was wanting to upgrade to a 4bbl. I was wanting to know what this could do to the mustang. Would it hurt it in any way or would it help.

 

Just by itself (a new 4bbl intake and holley 600)...it will help performance a little. It will also decrease his mpg.

 

I had a 65 with a 2 and hated it. couldn't tune it right and had problems. Went with a 4bl and love it. Yes I get less gas milage but it's still about 15mpg when I dont lay into it all the time which is good enough for me.

 

also, actually, the early 2 barrels were not very efficient at all. Yes with a big 4 barrel on there it wont get as good as gas mileage, but it wont be that big of a difference in overall fuel efficiency.

 

stay away from holley they require alot of tuning out of the box, edelbrock come already tuned, i have the same car except it came with a 289 2bbl and when i upgraded to a edelbrock performer intake and 600cfm edelbrock carb i had a great improvement in performance, the difference may not be as great in his because my old carb was junk

 

600CFM is too much for a stock 289/302. You'll get much better throttle response and efficiency out of a 500CFM carb or, better yet, the factory original Autolite 4100 (overrated at 480CFM).

 

im loving the 600cfm and i wouldnt consider dropping it at all, its very responsive and its the best carb edelbrock makes. while 500cfm might be better, im fine with my 600cfm