Apparently they have discontinued the M4F?Patricks used to sell them. Or at least they were selling one labeled as such.
If you can get a stock 261 grind, that would be nearly identical.
The 254 sounds like the way to go if you want to keep the torque. Or just reuse the stock camshaft.
I don't know what the specs are for the F290, but I know the F298 is a 268 degree cam. Way too much for what you're trying to build.
Clifford and Tom Langdon also have camshafts available.
Delta cams can grind one also.
RR,
Do you know what you want to run for a cam? Do you have a target compression ratio in mind?
For street use cast pistons and rings are fine.
Bowl porting will help more than the slightly larger valves would.
