Im upgrading from a vaccum secondary holley to a DP.

My engine is just a run of the mill 350, Performer RPM manifold, 416 heads ported, RV grind cam, and heddman headers to its y-pipe and a cat back.

is the 650 worth it, or will a 600 do just fine? Its not a track car, I drive it. probably see the track once to see what it runs.

 

A case could be made for either one. A 600 will be "big enough" for a mild 350, while a 650 wouldn't be "too big" but would support future upgrades better.

If your torque converter is a typical stock low stall (like 1200 RPMs), then the 600 would definitely support WOT from idle better.

 

If it's mostly a driver car (not much track), why aren't you sticking with the vacuum sec. carb? Do you like to pay for extra fuel?

 

Maybe I should do a 650 then, cause my THM 350 is getting rebuilt, with a higher stall for when I change cams in the spring to a comp cams XE268, and probably long tube headers while im there.

A DP doesnt use all that much extra gas does it?

 

i always thought DP carbs used alot more gas. but i could be wrong.
and what is the difference between a DP carb and a non DP carb?
iv always woundered about that.

 

Operating on the primaries, a DP won't use any more gas than a VS.

 

so you think a 650 wouldnt be to bad of a choice if im changing cams and stall soon?

its a 100$ dfference between the two

 

You can get a refurbished 4777 from Summit for $320.

 

Get the 650. You can always upgrade the main body to a larger size if you need to at a later date.

 

Why not pick up a used one off ebay for 50-75 bucks and get a rebuild kit. Good as new. There's literally millions of those carbs sitting around.

If you've never done it, its a great learning experience, its easy, and you'll understand your carb much better. You could pick up a used jet kit too.

A 600 will still support 400hp well on the street. But if you plan on getting some better heads someday, I'd get a 650.

For the street, you will always be happier with a smaller carb than a bigger one. Now if you wanted to spend some bucks, you could get a real nice built 750 with annular boosters, gain some hp, and may not lose and bottom tq. But were talkin over 500 bucks probably and probably not worth it to you.

 

thats exactly what i did, eBay. Buy it now for 50$ I rebuilt my 600 on there now. it was a good time, this one will be fun to.

But for right now until i get a new hood(2" cowl). Im going back to my non CC q-jet and performer manifold, Versues my RPM which i have on there now, I cant run a aircleaner.

speaking of my Q-jet, my car was not oringally a carb, and I had the choke not hooked up last time cause i didnt know were to wire it from.

Do I just put a wire in my fuse box so its hot when the car is on, then run that to the choke?