I'm going to get "Roasted " for this I know !! 400 thoughts ?

OOOOK . Back story first. I have 69 Dart that I've had for far to long ( last drove is in 1999)
the car has been apart forever and now I'm trying to put it back together for next year .
like many of us I'm on a Budget and funds are tight .
I have a 73-400 that I'm thinking of using for a yr / 2 to get the car moving and work the bugs out. I want the car to have a great sounding idle (rough) Its going to be a stock 400 with 906 heads/cam/ headers 4:10 Dana and 3500 stall convertor .
I wish the 400 had more compression but they dont.
I'm thinking abut the Comp cams CL21-602-5 Thumpr cam ( 507/494 ) do I have enough piston clearance ??
I know its not going to be a great combination for this set up but If I'm being honest im more interested in the " sound " of the car then the performance ( for next year) future plans call for a 400 something stroker but because I have the rest of the car to reassemble its not in the budget for next summer and I'm tired of the car sitting.

thoughts?