chevy 355 low compression question?

OK guys I am new here and looking for help. I have a Chevy 355 that is in my dirt track car. We were having problems with it blowing blue flames out exhaust and popping on deceleration. We thought it was header leak and lean mixture. We tried everything even timing. Well long story short we found the problem in the distributor the mechanical advance lockout was allowing the distributor to retard to about 17 degrees btdc when it should of been at 34. We ran two nights this way. I have now checked compression and there all at 100 except for 5 and 7 they are at 95. I didn't check the compression when I first got the engine I kick myself in the but now. But to me these numbers sound low I was thinking I should be up in the 150s+? the motor is built to be a 9:1 compression motor. Here are some of the specs Gm 3.480 crank had been sent out and counter weights cut and nitride coated gm 350 block prepped 0 deck piston height is + 002 out 4.040 bore . Scat 2 -1cr5700 rod pushrods lingth 7.950 piston -7cc
Felpro 1142 .041 thick 4.100 bore head gasket clevite ms-909p-10 main bearings rods torque 45 lbs .0047-.005 stretch mains 70 ft lbmain .0055 thrust
Rings total seal cr3690-45.
Rod bearings clevite cb-663 p-10 .23 Side clearance bullet cam Chs 278/286-064f at .50 in 248 exh 256
1.5 rocker ratio exh 532 lift in 353 cam is in at 102 heads are done with stainless swirl polish valves true 76 cc lifters are bullet with ls9925spl with oil hole