[6 Grrrs]

Originally Posted by 6 Grrrs

73 455 block .030" over
KRE 310 cfm 74cc d ports
Cometic MLS head gaskets
11:1 static compression
Custom wiseco pistons
Eagle rods
Rollermaster timing set
Bullet solid roller custom cam grind w/crower lifters and 1.65 rockers
KRE northwind intake port matched
Holley Stealth EFI with Dual Sync distributor and Tanks Inc tank with Walbro 450 LPGA pump in tank
MSD 6A ign box
Flowkooler aluminum water pump
And many, many other items for assembly

565 peak HP/580 peak TQ, 462 average HP/539 average TQ from 3000-6000 rpm

Intent was a solid street motor with broad torque curve and reliability is critical. Worked with Gary Cygan (Cygan Speed Engineering) thru entire build. He even did final assy after I built the short block 2 years ago and lost interest for some time.

Very happy with results, now just need to get in car. Car is 66 GTO hardtop with 4 speed

Update on this setup. Excellent street manners. Very driveable even with 3.36 gears and the wide ratio Muncie. Put about 3000 miles on it.

Been running great, pulled engine/trans and front clip from car. Upgrading trans, engine had oil leak and taking 'factory' a/c out and going back to regular heater setup.

Decided fuel pressure was a little low at the dyno session in 2017, and wanted to see the oil leak. Found leak (lifter valley pan) and fixed and then did some FP and timing tuning and ended up at 575 peak HP, 598 peak tq, while still running 93 octane pump gas. Did go thru all the valves and found one intake valve was .002" out of where they should have been. All others were almost right on according to my notes from 2017.

Then sprayed it with a 100 shot of nitrous and saw 662hp on first pull. After final tuning was 665hp and 675tq.

With a Richmond OD 6 speed, this thing will be a blast.