Building a 2800# bracket car based on a production 400 block and factory steel 350 crank. The motor will get AFR heads, Crane roller and all the other good stuff. Will also be running a Jerico 4 speed, ladder bars and 9" with all the good internals. What would be a good target HP and RPM for decent motor life. I figure if I build it to the 550-575 @ 7500, it should last a few of race seasons with yearly freshening. Any comments?

I would replace the factory 400 block with a Dart Little "M" block and replace the GM 350 crank with a Callies Dragon Slayer 3.48" stroke crank, and use a set of Crower Sportsman rods or better for that motor.

are you planning on balancing that stock crank? what are your specific class limitations? how much are you allowed to do to the bottom end? what sort of budget are you working under?

the blonde weasel
san diego, CA

For your combo, 550 is realistic if you have some good compression. Say 13 to 1 or better.

Chris

Tri-cities in Tennessee?? There is 3 city`s in Tennessee??

( I had too!! I only thought there was 2 !!Peace my friend ..smile )

Compression will be in the 13 plus range. The crank will be balanced. No limitations on the bottom end. Budget is 5-7K. Would rather not soak almost 3K in the block and crank, unless I absolutely had to. No doubt about the superiority of the aftermarket block and crank. I could see it in a roundy-round car, but this is a quarter mile drag car.

Generally stock components run out of life at about 500 Horse, and 400 blocks are not notoriously strong examples of chevy production blocks. Most of your money will go to the bottom end of this motor, as well it should, because with that much money into it, why would you risk running even a single sub-standard part? The last thing you want to fail is your block.

With those R's and that amount of horse, 7k is probably a moderate estimate. You're going to need a good amount of high-dollar parts (stud and main girdles, double valve springs, probably a roller cam, high buck heads, and a nice carb and fuel system to keep up). I've always marveled at the difference in price btw a 425-475 horse motor and a 525-600 horse motor.

K

It's a Tri City 2x a year, when we fill Bristol Motor Speedway!!! That doubles our population....

Chris

By the time you have your GM 400 block checked out and the machine work done, you probably won't be saving that much money over a Little "M" block. I would'nt worry as much about the GM steel crank as the stock block. They are known to crack in the main web area at the HP, compression, and RPM areas you're talking about. You can get a Callies Dragon Slayer for around $600 to $700. It has the same machining and heat treating process as Callies $1,500 to $2,000 dollar light weight cranks. It's cheaper because it only comes in limited strokes. If you do use the stock steel GM crank, have it magnafluxed ocassionally to check for cracks.