Thread: How pissed should I be, 454 instead of 427

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Hey guys, we just bought a car that we were told had a 427 in it, but trying to find out more of what I have I went out there to get the casting numbers off it (yes, should have before hand, hindsight etc. etc) and the number is 3999289. All the charts show this as a 2 bolt 454 instead of a 427. I'm thinking I should be really pissed, but saw in one guys post that he had a corvette with a 427 but that casting number. ??? hopefully somebody here is a chevy guru

also, heads are 3993820, oval port, are these good, bad? for power.

the 289 block can be a 427 or 454 + other size cid the bores are the same for the 4.250 for the 427 and 454 .why should you be pist if you have a 454?are you sure... you have a 454? there was many 454 blocks that were built using the 366/427 tall deck cranks and396.402 .427 cranks+a454 block to make a 427 .if it has a externally balanced damper and fly wheel then it a 454. less someone has re work the gm crank with heavy metal .or has a after market crank then it could be any size bbc up to 512 cid or a bit more with bore size and crank stroke .so block casting numbers do not help much i built alot of 489 and 496 out of the stock engine blocks.i have and seen alot of 454 blocks made in to 427s.as for heads ? whats been done to them ? what size valves ? what rpm? i used O port heads they work fine to a point

I will have to look more at it tomorrow. I just know the guy said it was a 427, doesn't remember any specs on it. supposedly 450-500 hp. thanks a lot, makes me feel a lot better

Back in '77 we ordered a grate 427 from GM, 7 months later my brother and I moved to Ca, and had it delivered to us in Ca. Yes it took 9 months to get it. We were told it would only take 10-21 days to get the motor. They said that they needed to make more pistons to assemble it! I don't know about now, but back then you had to pay for it in full before they would order them. But now we lived in Ca and sold the car before we moved!
After all the waiting We put a full frame into a '72 Vega and made a Pro Street out of it. and bought all the parts including the flywheel got it together and to fire it up, and it shook like hell! Took it a part and checked the guts and they sent us a 454! And then they wouldn't exchange the flywheel because it was now used, or even give us new gaskets. Because we bought the motor from one GM dealed and got the flywheel from the one in Ca, where the motor was delivered to!

Pat

so these heads I read are only good to about 550hp. but I figured to go up we'd have to change heads. the external balancer, it's on the back side right?

How does it run, that would be my main concern. rather have a strong running 454 than a dying 427.

Originally Posted by Dago Red

so these heads I read are only good to about 550hp. but I figured to go up we'd have to change heads. the external balancer, it's on the back side right?

you may be looking at doing more then heads if your pushing past 550 hp . yes you will see the counter weigth on the fly wheel and its on the back of the damper as well and all stock GM ex balancers are 8 inch thats one of the fast ways to tell if its a 454 but the hp 427 did use the 8 is well with no counter weight in the427 damper.if you have a stock gm 454 crank in less someone did alot of work to it...then it will need a ex fly wheel and damper