Here are some specs on my mild 455 bracket engine. Now retired from racing, it will be driven on the street to local cruise nights and car shows. Hard-core race engine? Not even close.
1974 455 std. bore, pistons sitting at zero-deck (ranging from zero to -.005") from the factory. Original factory stock cast pistons/rings/rods/bolts/crank/bearings/balance job are all still intact, this short block is completely untouched.
Hard to find a good 455 like this, I paid $100 for the entire running engine and then harvested the shortblock. I'm a thief.
1974 stock baffled oil pan, full-length stock windage tray, Mellings M54DS oil pump, HO Racing hardened oil pump driveshaft, stock oil filter adapter with the bypass plugged using a 3/8 pipe plug.
1971 #197 455 HO heads, pocket ported by a previous owner with a slight port clean-up, just enough to remove maybe half of the 'as cast' look inside the ports. The exhaust crossover is blocked off with an aluminum plate on the intake side, crossover passages are not filled. Milled .025", my guess is the stock 111cc chamber is now 105cc.
Compression ratio calculates (guestimates?) to
8.6:1 with a .040" crushed head gasket.
HO Racing HC-03 hydraulic cam and lifters (244/252@.050, 113 intake/120 exhaust LCA .550/.554" lift w/1.65 Erson stainless steel rollers). HO Racing 5/16" chome moly pushrods and VS-12 springs (1.71" installed height, spring seats cut) and stock retainers. Cam installed 4 degrees advanced using a Cloyes Tru-Roller 3-keyway timing set.
650 Holley double-pumper carb with stock jetting, only mod is a 50cc accelerator pump on the secondary side. Edelbrock Torker II intake with exhaust crossover removed and water crossover seperated, no porting/port matching or internal mods. Carb sits on a 1" open phenolic spacer. Stock 1974 aircleaner with a 2nd snorkel added, both are plumbed into the cowl for cool air.
Distributor is a stock single-point with no vacuum advance and the mechanical advance mechanism locked out (38 degrees advanced), fired by an Accel coil and an MSD-6A box. It will be replaced with a recurved stock single-point distributor with working vacuum and mechanical advance for street duty, the MSD-6A box will be retained.
HO Racing round-port Tri-Y headers (1-3/4" primary/2" secondary/2-1/2" collectors) dumping into a 3" home-made stainless steel exhaust with 3" #17547 (20" long case) Walker Dynomax Ultra-Flo Welded stainless steel mufflers, 3" tailpipes over the axle. There is no exhaust crossover of any kind on this system, it was built using all mandrel bends.
Drivetrain consists of a TH400 w/transbrake and reverse-pattern manual valve body, stock flexplate/10" Continental converter (3500 flash stall), Ford 9" rear w/3.89 gears & 31-spline Detroit Locker/stock Ford axles, 28X10 Goodyear slicks.
Best ET near sea level at Carlsbad Raceway on a warm August morning: 12.055 @ 110.29 MPH, 1.668 60' time. 1964 GTO 3550# race weight w/driver, a 5200 RPM shift point keeps the rods inside the block and produces the best ET.
This low-compression 455 makes an honest 400 HP, runs on 91 octane.
Same engine, updated a little for 2008 with a '71 455 HO intake and '77 800cfm Q-jet carb (big thanks to Cliff Ruggles) topped off with a '70 GTO twin-snorkel aircleaner. A recurved stock points distributor with vacuum advance (big thanks to Rocky Rotella) replaces the old locked points distributor. A new Rodney Red aluminum radiator with a '66-'67 upper hose location now takes on the cooling chores.