Chevy 603 Crate Motor Performance

More Power for Your ‘603 Crate

'603 Crate with "UnderCover Porting".

The stock intake port flows just 188 cfm – that is worse than stock “double hump” heads. With our “Undercover Porting” the intake air flow is improved to over 218 cfm and the port still looks stock!

Unlike the ‘604 Crate, which has excellent cylinder heads, the heads on the ‘603 Crate are just plain awful from a performance standpoint for anything over 5,500 rpm.

If you want to get a huge advantage over the car next to you, get your heads “UnderCover Ported“. Or, don’t get them modified and run just like the rest of the pack.


“Undercover Porting” to YOUR Bare ‘603 Heads

Send us your new or used bare ‘603 heads. We will perform our “Undercover Porting”, which includes CNC machining, modifications to the intake ports, exhaust ports, combustion chambers, “Cover Up” work, sizing the valve guides and machining the valve seats for 1.94″ x 1.50″ valves. Cost is $995.00 labor only to your bare pair of ‘603 heads.


See also: Cylinder Head Resources

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