Thread: 454 Towing/ Farm truck

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That cam will require minimum 9.5:1 static compression ratio, which will require a piston change.

If you want to keep the stock pistons in the block, you will have to use less cam. Although flat tappets are from the last century and no longer have a place in street drivers, particularly BBC street drivers, here is a flat tappet hydraulic cam like I might recommend for you....

Crane Cams, grind number H-248-2, part number 133971. Operating range 600-4200 rpm's.
Brute low end torque, smooth idle,daily usage, fuel economy, 1200-2000 cruise RPM,
8.0 to 9.25 compression ratio advised (Your motor is likely somewhere between 8.0:1 and 8.5:1 static compression ratio.)
Advertised duration 248/260
0.050" duration 192/204
Valve lift 0.453"/0.484"
Lobe separation angle 110

This is the cam timing that the motor wants and needs. Thing is, there are no comparable hydraulic roller tappet cams that fit these numbers. Every roller cam I looked at wanted more static compression ratio than the Crane flat tappet model shown, so like I said, if you want to run a roller or more cam than I have recommended here, you will need a piston change.

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