Did you trim the center bolt support gussets on the stock valve covers? I've got Comp Cams Pro-Magnum 1.6’s, on a solid roller cam with 0.590” gross lift on intake and exhaust, and no problem with the trimmed stock covers.
Only complaints I’ve seen over the past 20 years on the Canton oil pan is leaks, sloppy fabrication. No idea about the suitability for road racing. The stock LT1 oil pan has proven itself adequate for drag racing. I run a stock pan. Buddy of mine ran stock pan on an 1,125 HP 97 30th Anniversary SS, and was happy he only wrecked a stock pan when he dropped the car hard a couple times, from a 3-ft wheelstand. Cheap to replace......
1994 FIREBIRD FORMULA
381ci all-forged stroker (Callies Stealth, Oliver billet rods, BME 2618-T61 nitrous pistons) - 10.8:1 - CNC LT4 heads/intake - Comp Cams solid roller - MoTeC M48 Pro engine management - 8 LS1 coils - 58mm TB - 74#/HR injectors - 300-shot dry nitrous - TH400 - Gear Vendors 0.78:1 O/D - Strange 12-bolt - 4.11 Pro-Street gears - AS&M headers - true duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP / 800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117 MPH straight motor