I got stuck repairing/rebuilding a gen V 454 that another shop pieced together. the cam in it is a Howards 120031 which shows the specs as following

Cam Style: Hydraulic flat tappet Basic Operating RPM Range: 1,200-5,200 Intake Duration at 050 inch Lift: 215 Exhaust Duration at 050 inch Lift: 225 Duration at 050 inch Lift: 215 int./225 exh. Advertised Intake Duration: 269 Advertised Exhaust Duration: 279 Advertised Duration: 269 int./275 exh. Intake Valve Lift with Factory Rocker Arm Ratio: 0.516 in. Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.527 in. Valve Lift with Factory Rocker Arm Ratio: 0.516 int./0.527 exh. Lobe Separation (degrees): 112 Camshaft Gear Attachment: 3-bolt Computer-Controlled Compatible: No Valve Springs Required: Yes Camshaft Manufacturers Description: Great low and midrange torque. OK in heavy vehicle.

the boat has stock cast mercruiser manifolds, what are the thoughts with this cam as far as reversion with the stock exhaust. the engine also has an edelbrock performer rpm air gap intake and is 9:1 compression. it already has one cracked head and three cylinders with valve seat issues so I dont want to reuse the cam if it was the cause of some of the problems.
thanks

Apparently bob Madera is the man. Rmbuilder on the board. I haven't personally used him but when I do build motors he is getting the cam and valve train work. Haven't read anything but mega positives about this guy

I am hoping he will chime in. I am worried about every thing I found on this engine (loose plugs, loose bolts, half a gasket under the carb, 1" mercruiser flame arrestor, stock exhaust manifolds, loose distributor, etc) that am nervous about using anything they put in it.

You shouldn't be reverting with that cam. Its pretty weak. Not really the cam Id run in a marine 454 from a performance standpoint though.

not sure how much performance I can get any way. I am stuck with the stock exhaust and I have to find a much shorter intake than the air gap performer rpm so I can get a taller flame arrestor on it so it will breathe (owner wont let me cut into the hatch). the boat is an older Campell day cruiser so big power is not a priority but he wants it to run strong and the engine in it only made it 25 hours before the valves gave up.

Here's Bobs phone no. You don't need to wait for him to chime in.
Bob Madara aka rmbuilder 585-654-8583