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#1
12-22-2020, 11:49 PM
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4:00” or 4.21?
Looking at a new build same block, 2 cranks., a 69 428 crank in a 1975 455 2 bolt block or a 4.21 crank in your 75 455 block. at .030 bore, .010 rod/mains. Your plans for the engine are serious street/ strip action. You want to build a strong lower end end strong enough to handle a hyd roller cam with duration somewhere around 245/255 duration at .050 and around ~.580” lift Your plans include either Ross forged pistons or ?. I will be using a quality 6.7 rod. Rear gears will be around 3.73 , appropriate 10”converter chosen as well. Exhaust will be 3" with Doug's headers. The heads will be aluminum round port 290-305cfm, Intake will be a RPM OR Torker II
So 1 ) Use the 4" crank in 455 block + .030. 440 2 ) Go for cubes and build a 2 bolt 462 .+.030 Car a 68 Firebird. Is there a difference of these 2 motors or not so much and why you chose either!
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Jim Moshier 1971 Grand Prix 462ci SD Performance 6x heads 1962 Catalina 389 1968 Firebird 400-455 I haven't decided "If we ever forget that we're one nation under GOD, then we will be a nation gone under." - Ronald Reagan Last edited by Jim Moshier; 12-23-2020 at 12:41 AM. |
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