[ArticGTO]

Anyone have some advise on Carburetor for my goat?

Just had motor bored .020 with new pistons, new lifters, rebuilt heads roller rockers, re-balanced with new ring gear and harmonic balancer, and higher duration cam.
I am using stock intake with I beleive has spread bore.
Trying to figure out if I need an adapter plate if I use a Holley 0-80450 - Holley Model 4160. Has anyone used this carb? Would the carb fit on stock intake without an adapter plate? Would I have a performance issue if I used just a square hole plate or should I find an adapter plate to match the circle holes in stock intake? I don't have the stock Rochester carb.part #7040264.
Want to make a driver car but want to have power when I need it.

[carbking]

The 80450 is listed as a 600 CFM square bore carburetor. This should break down as approximately 300 primary, 300 secondary.

The stock 7040264 is normally thought of as a 750 CFM spreadbore carburetor. This breaks down as approximately 150 primary, 600 secondary.

By using the stock manifold (150/600) with the square bore carb (300/300) you can figure basically the smaller of the two figures for both primary and secondary. You now have approximately 150 primary plus 300 secondary, or a 450 CFM carburetor/manifold combination.

Using the recommended Holley adapter will return some of the CFM, but causes the air/fuel mixture to make extra turns which an air/fuel mixture really doesn't like to do.

If you like Holleys, by all means use one; BUT change to the proper manifold. Personally, I think the 600 is a bit small for your combination. A 750 would be a better choice (again, change the manifold).

I would suggest you would be money and performance ahead by any of the following:

(A) acquiring the proper Q-Jet (spread-bore)
(B) having Cliff build a different Q-jet specific to your application
(C) using a Carter TQ aftermarket spread-bore (my personal choice)

Jon.

[ArticGTO]

Thanks for your advice!!
Looking into a Q-jet as we speak so I can go back close to original!!
I really am not impressed with aluminum intake!!
I like the stock stuff!!

[cuz68]

Originally Posted by carbking

The 80450 is listed as a 600 CFM square bore carburetor. This should break down as approximately 300 primary, 300 secondary.

The stock 7040264 is normally thought of as a 750 CFM spreadbore carburetor. This breaks down as approximately 150 primary, 600 secondary.

By using the stock manifold (150/600) with the square bore carb (300/300) you can figure basically the smaller of the two figures for both primary and secondary. You now have approximately 150 primary plus 300 secondary, or a 450 CFM carburetor/manifold combination.

Using the recommended Holley adapter will return some of the CFM, but causes the air/fuel mixture to make extra turns which an air/fuel mixture really doesn't like to do.

If you like Holleys, by all means use one; BUT change to the proper manifold. Personally, I think the 600 is a bit small for your combination. A 750 would be a better choice (again, change the manifold).

I would suggest you would be money and performance ahead by any of the following:

(A) acquiring the proper Q-Jet (spread-bore)
(B) having Cliff build a different Q-jet specific to your application
(C) using a Carter TQ aftermarket spread-bore (my personal choice)

Jon.

Jon i did not know that carter made new spread-bores, What is the cost of them? and where can you find them? Are they bolt on and ready to go? Thank you Randy.

[carbking]

Randy - Carter made in previous years part numbers 9800 without EGR port and 9810 with EGR port and cap. Both are 800 CFM with GM linkage and electric choke. A little looking should find a vendor that has them.

Jon.