Rebuilt 350 - detonation --> Cam swap?

[Greasey Harley]

Okay I rebuilt a 350
87 TBI block, .060 over, flat top slugs with 4 releifs
65cc TBI "193" heads, These heads are susceptible to detonation (I later learned)
10:1 compression
Compression test reads 185psi (rings aren't seated yet, about 200mi on engine)

I put a "torque cam" in it trying to make a good truck motor. Problem is, I have my timing retarded to 8* initial, and 28* mechanical and still have slight detonation.

Cam specs are:
Elgine MTC-1
Intake Duration at 050 inch Lift: 204
Exhaust Duration at 050 inch Lift: 214
Duration at 050 inch Lift: 204 int./214 exh.
Advertised Intake Duration: 278
Advertised Exhaust Duration: 288
Advertised Duration: 278 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.420 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.433 in.
Valve Lift with Factory Rocker Arm Ratio: 0.420 int./0.438 exh.
Lobe Separation (degrees): 112


This motor doesn't like this cam, so my options seem to be,
1)decrease compression----> different heads with 72cc chambers I DON'T REALLY WANT TO SWAP HEADS

..or

2)swap cams

I'm thinking I need a cam with around
Intake Valve Duration (degrees @ .050" lift) in the 220ish range to compensate for the high CR

I don't want to swap springs if I don't have to, and I would like to keep the RPM Power Range as low as possible.
anyone have any cam suggestions ?
Can I fix this problem with a simple cam swap?
Should I just buy different heads? ---Really don't want to.