Soroush, I have a 69 428 SCJ 4spd also 4.30 and would be interested in comparing some thoughts with you. Mines at redline on tach in a blink
PILOTJPW1, I can imagine, big blocks torque will push through just about anything, are you hitting the redline because your spinning your tires as soon as you get on it specially with 4.30 gears? I dont think I have ever been in a big block car with such short gears must be fun!
though big blocks do run out of revs a little quicker than the small blocks they make up for it in the amount of torque they put down.
by comparison my boss makes no power before 3500 rpm and even at 4000 its still not fully awake, once you hit 5000 rpm it feels like, to steal a phrase from Jeremy Clarkson, "god is here..... and he is angry!" and it pulls harder that anything from that era until 8000 rpm
driving such car makes for some interesting issues as I learned when I first brought the car home I realized even tho you can rev it to 8K rpm its probably isnt the best Idea I remember missing a shift going past 8500 and spending the rest of my weekend replacing pushrods and a broken rocker arm and relashing all the valves. didnt hurt the motor but still was not fun. also when the power does come on its so different that any other car from the era mainly because you dont expect a big rush of power at 5000 rpm so it can take you by surprise and it often breaks the tires loose so you have to be ready ( it almost feels like a turbo car)
you can hear the tires breaking loose on my second vid as Im approaching you can hear the pitch of the motor change at the top of second gear, I think I shifted into third around 7200 rpm and on the first vid you can see when you rev to about 7K rpm and shift youre back to 5K rpm just to keep the motor in its power band
all and all the boss motors are really different animal than anything else that were made around the same time.
and even tho the car is not fast by todays standards I can tell you its more fun than 99 percent of fast cars out there.