Thread: 70 Monte 454 Fuelie Bad Combo Questions:(

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Hello all!
First post here. Looking for answers to a poor running 454 combo.
70 Monte Carlo 454 Turbo 400 2500 stall. Car is resto-custom frame off. Around 4000 lbs.
Started with a marine block (pass perf Mk4 cast in rear). Stock bore size (never bored).
Forged GM crank (not nitrided...forgot part number but IIRC it's a good one!)
New GM performance rods with 7/16 rod bolts.
TRW Speed Pro forged pistons L-2465F. 10.2 -1 compression is what I had it figured at 5 years ago when I built it.
GM performance aluminum heads with the large valves 12363390 2.25 intake valves oval port
Lunati 50266 Roller Cam Hydraulic http://www.lunatipower.com/CamSpecCa...rtNumber=50266
Accel Gen7 fuel management dual sync dist, sequential fuel control. Accel intake oval port aluminum, I spent 10 hours match porting the intake to the heads on a milling machine. 1350 CFM oval blade throttle body.
Holley ignition box (since discontinued).
Long tube headers 2 inch homemade. 28-34 inch primaries. Dual Random Technology CATS going into 2.5 inch dual exhaust 40 series mufflers.

I forget all the specs, I'll keep adding. My issue is a terrible spark knock that starts around 2200 RPM. I've pulled the timing down to 8 degrees in this area. Fuel 12.5-1 WOT with wide band O2. Things are ok if you can get thru this bad spot although this engine doesn't feel like it is making more than 350-375 HP. It should make just under 500. I have added a 2500 stall converter which did help, now I am custom tuning the shift points with a governor weight/spring kit.
This engine burns oil. I knew it would use a bit of oil but not this much.
At this point the engine has about a thousand miles on it and my next step is cylinder leakdown, compression cranking tests to reveal leakage. If so I'll tear it out.
I thought my cam choice would be ok for a street, strip car. not sure now.
93 octane gas may NOT be enough for this pig....wondering.
Please help with next steps. My thoughts are to throw an HEI and carb on this to be sure that some of my issue aren't tune related. My tuning background is small block with Holley Commander 950 and LS1,2 stuff and EFIlive. Have taken 2 tuning courses (1 with Greg Banish).
My background is European automotive and no problems doing engine/transmission work (until now).

Thanks for reading. I'll dig up more specs. Labor of love at this point.

John