4bbl 350 intake question

[petermarcus]

I have a decent handle on spread vs square carbs, and primary and secondary bores, but the intake manifold interfaces throw me. Might be a dumb question, but for a 4bbl spread, what’s the difference between the opening for each of the four bores vs the two open ovals? I assume there are pros and cons for each? Thanks…

 

[ROY WILLIAMS]

I have a decent handle on spread vs square carbs, and primary and secondary bores, but the intake manifold interfaces throw me. Might be a dumb question, but for a 4bbl spread, what’s the difference between the opening for each of the four bores vs the two open ovals? I assume there are pros and cons for each? Thanks…

SO CORRODED A MESS !!!!! DAMAGED IT ....
MY CARB IS 1978 AND TODAYS ... NO CORRODED ...... THE OCTOBER EVERY YEAR CARB TAKE IT OFF THE TOP CARB ... CLEANING IT ,,, AND THE MMO OIL DID THE CLOTH ......ALSO THE TB THROTTLE SPRAY ...

 

[Scott06]

I have a decent handle on spread vs square carbs, and primary and secondary bores, but the intake manifold interfaces throw me. Might be a dumb question, but for a 4bbl spread, what’s the difference between the opening for each of the four bores vs the two open ovals? I assume there are pros and cons for each? Thanks…

I don’t think there is much difference except the first photo has a universal mounting it can take spread or square bore carbs. There are two sets of threaded holes for mounting the different pattern carbs. One on the right looks like a std GM set up for quadrajet carb only. A square bore like holley or edlebrock wont fit it .

they are both dual plane intakes, and while plenum volume can affect performance in a low rise intake like this won’t make much difference

 

[cyclops222]

It is not really important which you use or have. Unless you are going to race it in a class.

 

[petermarcus]

These were just pics from the internet, I’m looking to get a new intake soon and I keep seeing these different cutout shapes. Thanks for the info