rebuilding a big block??

[BigBlock454]

Hey everybody, just have a question for anybody that has any knowledge on this...

My friend has a 402 big block, well pieces of it anyway... he thinks all the parts are all there and from what he tells me, and he wants to rebuild it... this is what he says he needs to get done

the whole block is rusted, and therefore needs to be boiled, etc to remove the rust
the pistons are locked, and need to be repinned
the heads need to be reconditioned
and he need a new cam, new rings, new valves, new gaskets

does anybody know approximately how much it would cost to get rebuilt, or would it be better off if he just buys a whole new motor, any suggestions would also be helpful, as I am pretty clueless on working on motors, he at least has a semi-clue what is going on with them... thanks...

[fastrThanU]

i can't tell you exactly, because i haven't seen the motor. it sound to me as if you're describing a block with frozen pistons (pistons are physically frozen in the block) you're going to without a doubt need a complete overhaul. bring it to a performance engine rebuilding shop (NOT a normal shop). have them look at it. if it is in fact worth the $$ to rebuild, it will need to be hot tanked and magnafluxed to determine if the block is cracked or has any weak spots. aside from that, i can't really tell you much. rebuilding a motor can cost about $2500 depending on how many parts you have, what condition they are in, if they need machining, porting, and how much you want to build it up. a friend of mine has a 468 big block that he has put over 10k into.

good luck.

[Crackerman]

unless it is a numbers matching resto 402 bigblock i wouldn't spend a dime on it, u would be better off finding a running 454 or 396 that needs little or no work for cheaper than u would spend on a 402 that has several torque issues when it comes to competeing with a 454/468.

[fastrThanU]

you could always have them bore the block out when you have them hone the cylinders. the 402 may not have as much torque as a 502 etc simly because of smaller cylinders, but it can rev higher because of less rotating mass. that is one of the main reasons why some people actually prefer small blocks over big blocks besides the issue of a lighter engine... but it would definetely be more cost effective (not to mention not having to deal with machine shops) to sell the motor, and buy a running one.

[BB 402 CHEVY]

I have a 72 402 Big Block that I had rebuilt for around $3500. It is a full roller motor producing 580 hp and 625 ft/lbs of torque. The guy that built it warned me that my trans and rear axels would not hold. Upon breaking in the motor, I scattered the trans (brand new B&M 400 turbo) on my street. I had a turbo 350 built and have yet to hurt it. If I would have built a 454 to produce the hp of this motor, it would have cost me around $5000. My advise is if you have the motor, you are 1 step in the right direction. But like the other guys say, there is no substitue for cubic inch. I also had the motor rebuilt because all of my numbers match. Good luck with your decision.

[-The Stig-]

Hey, he asked that question two(2) years ago.


I'm sure his decision has been made... and for future references. Try not to dig up threads that are older than three(3) months old.


Thanks... and I'll be locking this, it's policy.. nothing against you... So don't get offended.