375-396 Stocker valve springs?

[Frank Bialas]

Originally Posted by SS Engine Guy

Cast crank/ check each year. Anything that wasn't there the year before when checked toss it. Normally they will last 4 seasons. Make sure proper fillets are ground into the rod journals and the bearings are preped for that. 2 bolt block/ no problem. If not aftermarket block go with the thickest sonic test block and prep it with filler. The old 66' blocks were really thick. ATI or Fluidamper. Some overbalance at powerband range. Good pistons and pins. Carefull attention to detail on balance and general prep. Get someone who knows what they are looking for if using 3/8 rods and get rid of the parting line in order to mag properly. Use the best rod bolts and torque them at least 3 times during machine work and then stretch them to manufactuers spec. At next freshen up any bolts that the freestanding length is .001 or greater than in assembly log, toss them.

8200?....mine go thru the traps at that ,sometimes more and peak hp is up at around 7600 - 7800. (Peak hp is only a number to campare, peak torque is what is hard to accomplish). BBC intake ports are adequate for that number. The exhaust is the choke but with a well designed set of headers they will help that out if they scavenge well. (in the 1500-2000 dollar range for a header that works) Bullet Cams can help with some of the exhaust deficiencys. Get someone who understands the importance of a valve job to do the heads. With the new valve seat rule there is extra flow there too.

I understand the concern over piston/rod weight. Crank is rotating weight not reciprocating. Think of the weight of a 540 to 750 inch engine even with aluminum rods. Unless the rods are cyrogenic deep cycle they will weigh the same or sometimes more than a 7/16 chev. rod. Nitrous cars will usually use a heavier piston deck to be stronger in detonation situations. The biggest concern on the heavy rod/piston deal is the wrist pin on the intake stroke, when the piston stops at TDC and is pulled from a complete stop downward. That is why a good pin is necessary and monitoring them is critical.

You are correct. If you don't absolutely control the valve action with the proper spring you will run into clearance problems and beat the lifter into submission. I would tend to like a little more than not enough from a power and reliablility standpoint.

Just asking??? At what RPM does the RAT puke out peak torque???