Ive got a 1974 455 in my 53 super, It runs great but doesnt have alot of power, Ive rebuilt the carb and dist. The advances are working properly, timing is at 10 BTC(3.50 rearend). Is it normal for a 74 motor? Is the compression lower? since its a smog motor. Can I wake this thing up with a different cam?(and where can I buy one)? I have a 1970 455 sitting in the field but it will need a rebuild,does it have better heads? Thanks for any info Mike

I would wager a guess that your '70 motor would have better power. Mainly because it's a pre-emissions motor. However, you should try and find out if the heads, cam and intake off the '70 motor and use it on your existing motor. The parts from the '70 won't have EGR, and you can easily remove the AIR pump.

I'm not totally sure about all this, but it's a place to start

Good luck
Ben

The 70 engine has pistons with a shallower dish which is the way they got the compression. The 70 heads are also better.

Thanks for the help

head specs - http://www.atlantabuick.com/CastingNumbers.htm

piston comparo - http://www.buickperformance.com/pistons.htm

1970 has a LOT more power than 74.
.............HP..............TQ........Chamb...Com p
1970.....350-370........510.......69cc....10 or 10.5
1974.....190-255........355-370...71cc....8.5

some of this difference is due to the change to SAE power ratings but most of it is loss of compression and smog equipment. the extreme lower end of the 74 HP number is because 74 was the only year buick offered a 2v 455.

well, one great tip would be to close of the heat riser into the intake manifold and get the butterfly out of the exhaust. that would keep your intake temp down and improve your exh and int flow if you do it properly. wouldn't help your cold starting any though.