Thread: 75 454 Tall deck

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I have a 75 Tall deck 454 that I am having some issues with. Its my brothers old truck which I believe is the 346236 casting. It has large oval port heads which I have no idea if they flow worth anything or not. I just put a Summit racing SUM-K1301 cam in it.

Specs: duration 218/228 and the lift is .500/.500 with a lobe separation of 114.

Motor seems to run fine so here is my issue. When removing the old ugly Edelbrock iron intake that was on it, I found that it had SMALL rectangle ports instead of the large oval ports. I mean these ports look smaller than a SBC intake. I don't know if the intake is for a 366 or what.

I am sure the intake would be hampering the air flow into the motor as the intake gasket for the oval port heads easily encompassed the little rectangle ports. I have had some where between little and no success in finding an intake for the large oval ports and the tall deck. The oval port intake for tall deck that edelbrock sells is considerably smaller than the ports on these heads.

When I finally get an edelbrock intake with the correct sized ports its for a short deck and not the tall deck. I know Weiand has an adapter for tall decks but I HATE adapters and that will add more money to an expensive intake and I am back to are these heads any good or what? Any help would be appreciated.

I am looking at a S/A Rat book right now and it list the no. 346236 as a 9.8" deck height block 454 made in 1975 only.I believe a tall block is 10.2 ". This means that you can put any manifold you want on that motor without spacers.The cam sound's O.K. for a street motor . Oval port head's will also work fine on that 454. The intake you have sound's very odd.I don't believe it is the right one for that 454.Good luck with your motor.

I will have to verify casting numbers but I know for sure its a tall deck block. I bought the edelbrock std deck large oval port intake which the ports matched my heads nicely but nowhere near fitting the motor. I would just like a stock intake to fit this thing as its in an old truck and it currently has an edelbrock intake on it but it looks like its for a 366 as the ports are square and smaller than a SBC intake port. I don't know how well these 75 truck heads with large oval ports flow but the hole is twice the size of the intake port it has feeding them now.