[General Z]

My thread regarding the rebuild was getting pretty long, so I started a new one.

I rebuilt the engine again. I did the 421 mod, plugging the front two holes and drilling the other one.

Cast impeller water pump, with clearanced divider plate.

I had my heater core bypassed, but replaced it during the rebuild and am now using it.

I have all the AC baffles in place.

The engine is running hotter than ever. It was doing 210 tonight with just light driving.

I'm looking for ANY ideas. You can read my build specs below.

I do need to re-check my timing. I think I may need to advance it a bit more.

Thank you in advance.

My specs are below:

1967 Firebird Convertible

Engine: 1970 455 Block, bored .060
Bore: 4.2109, Stroke: 4.21

Crank: Pontiac factory crank, ground .010 on rods and mains

Pistons: Sealed Power forged pistons

Rods: RPM International forged rods

Heads: 1971 400 Heads, Code 96
Mildly Ported, Stainless Steel Valves, Dual Springs
96cc, Valves 2.11/1.77
Comp Cams roller rockers, Ratio: 1.52

Compression Ratio: 9.53:1

Intake: Edelbrock Performer, dual plane, port matched

Lifters: Summit Racing Hydraulic

Cam: Summit 2802

Carb: Holley 0-3310S 750cfm 4-bbl with manual choke. Using ½” carb spacer.

Rear End: 3.73 Gear ratio

Rear Tires: 216-65-15

Accessories: Power Steering, Power Brakes

Ignition: Performance Distributors HEI

Radiator: Aluminum 4 core, big block, with Mark 8 electric fan

Thermostat: Balanced 180 with extra holes drilled in it.

Water Pump: Cast impeller with clearanced divider plate

Transmission: 700R4

Torque Converter: Unknown

Exhaust: Hedman Headers, Dual 3” exhaust with H pipe

Oil: Rotella T 15W-40 + a bottle of Comp Cams 159 additive.