ok well here is the deal, i want a 355 combo.

i havnt been on the site in alittle while, so please forgive me if i bring up something that has already been discussed.

i wanna run a 355, 750 DP carb, with between 9.6 and 10 compression. forged flat tops, with 64 cc heads. i would like to run an Ultradyne 257/267 cam, but im yet to get in touch with harold about it. im looking for right around 450 horse, and i wanna put at least 375 to the wheels. id like to run a 350 trans, and im gonna be puttin this stuff in my iroc. any ideas on what kind of heads i should use? or what kind of parts? id like to run an AirGap intake.
money is no object.
please help me decide how to put down at least 375. if you have any combos around there with a 350-or-so motor, please post em

thanks for your help

mike

With flat top pistons, .040" quench, and 64cc your CR is closer to 10.2. I'm guessing the dur you gave is at .050". If so, even 10.2 is probably too low. If it is adv, then the compression is likely too high. Check out the DCR page in my sig. Matching the CR with the cam will make much more power than a mismatch.

My combo, on a good air day according to Prestage.com's calculator (http://www.prestage.com), puts about 400 to the tires. My combo is linked in my sig, also. I do have a mismatch, although not too bad, in that my CR is low for the cam. Should be 11.25 not 10.5. Also, I now have a 750 DP instead of the 850. The engine seems to like it better.

If money is no object, I suggest AFR heads or Brodex RaceRites. Go with a port size around 200cc. Any larger will cost you power.

Try to set the quench distance as tight as possible. You can safely go as tight as .028" (even .024" if you're daring) in a strip engine. For a street engine about .035" is a safe distance. Using 1.6 rockers on the intakes only will produce a bit more power. At the power level you're looking for, I suggest using aftermarket rods. Eagle SIR rods are a very good choice. 6" rods will make a bit more power, too. This is controversial but I think they help.

Mike,
I'd listen to Pat and research some other combos and experiences that are in this board's archives. I am sure you will find an excellent combo for your 355 application. It's almost impossible to get to talk with Harold anymore, but there is enough info on our board to order one of his cams thru Lunati - I think their numbering reflects Harold's old UltraDyne numbering system. I haven't run small blocks in a few years, but I always felt the best money spent for me was on AFR heads - they produce a bunch of power and I never had any problem with the many stock and super stock applications I had spinning to some quite high RPMs using very high compression ratios on many occassions. Keep searching and then decide what you want and put it together - build it and the performance will come!

thanks very much guys