stephenmsweigart

looking for an aluminum intake for 454 rectangular port spread-bore....am leaning toward edelbrock but can only locate those for oval port heads....can anyone help me out


steve
official and forever a newbie

Mooser

I think that'd be a pretty rare combo (spread-bore & rectangular port) to find.

What year is the car and what style of hood do you have?
M

The13Bats

That is tough, the rec ports are big breathing high rpm stuff and most of those cats wanted big huge carbs for that...hum.
Sucks but I guess you could try an adaptor plate.

stephenmsweigart

I bought a 1971 454 block stroked to 502 currently have a 4 barrel 750 cfm quadrajet that I'd like to use. The block is rectangular ported and am having trouble locating the correct intake. Can a square port be used with an adapter plate?

stephenmsweigart

1970 with l88 hood which would allow more clearance

The13Bats

Sure you can use an adaptor and then whatever intake your heart desires they make a lot of different adaptors, open center 4 holes, etc, the extra height will go along with the high rpm rec port heads, but I doubt it will all fit under a stock hood.

7t9l82

I don't know how your engine is built but a 500 cube rat motor with the rectangular port heads will probably need more than a 750 carb. I'm a fan of carburetor spacers to help tune an engine but wacky adapters can be a problem,not always but can.

The13Bats

I was just going with what the OP wanted, I too believe that the 750 might hold back full potential of a 502 especially with rec posts,

I have seen adaptors that didn't really mate up where they should, and then the company would try to get by with a gaskets but the name brand spacers are not too bad if one really wants to go that way.

stephenmsweigart

So my 750 quad will not be efficient....what would the recommended carb be for a 502? Guy rebuilding thinks it will be adequate....will it have a negative affect on hp or torque or both?

7t9l82

It would negatively affect top end power and limit your power range. I always ran an 850 an 800 would work out pretty well.

ddawson

830 or 850.

I use a 830 on my 496 and it was perfect. But I switched to a QuickFuel and LS6 intake.

The13Bats

The thing is the heads are the rec ports these are the big high rpm fellows the actually hurt low rpm especially torque, the engine has to be able to inhale and exhale, the 750 will "work" an 850 will work better,

Since the cat building your engine believes 750 is good I would ask why he doesn't feel to reach full potential he doesn't need more carb?

750 or 850 the engine is gonna be a terror when you get into it's higher power band....

427Hotrod

What's the rest of the combo? Rectangular port heads are high RPM deals even on 500 cubes. Curious what bore/stroke combo made a 502 out of a 454?

What cam is in it? How high do you plan on spinning it? Trans/gears etc....

JIM