I am building a .030 over 455 and using the #96 heads. I plan on milling them .050 as well as the intake side. My question is do I have to use different pushrods other than stock?? Cutting the head would seem to change the geometry of the pushrods. Also I am running 1.65 roller tipped rockers. Is there any mods need to be taken in consideration for using these? Any info would be greatly appreciated.
hello;welcome to the site.did you mill your block also?i prefer to mill the intake manifold.you need shorter push rods when you mill the heads or block. the aftermarket rockers can change the length required also. you should buy a push rod checker to determine the proper length.mark your valve tips with a felt pen to check position of rocker on valve tip.the roller tips can fail especially under high spring pressures. i would run scorpions "race" model full rollers.
i forgot to mention. i see you have multiple posts. the error message you recieve is a flaw in the site, typically [not always, lol] if you push send it will post even when the error message appears.
Thanks for the reply, I can mill my Performer RPM if that would be better. I will check into a push rod length checker.I am running comp cams 995-16 springs. I don't know what seat pressure these have but will check. Do you know the spring pressure limit for the roller tipped rockers? I already bought them. As for the multiple listings you were right I kept getting that error message, Thanks, Tim
Hello;Well, I would mill the intake. I suggest you send a pm to tuffnuff and ask his opinion.You certainly "can" mill the head intake surface but that can come with its own probs. It moves the intake surface away from the front and rear intake sealing surface on the block. I'd rather screw up a cheap intake than a set of Ram Air IV ported heads or whatever they might be, lol. Intakes are replaceable, cheap and easy to come by. Nice orig heads, especially the good ones, are getting harder to find all the time. ROCKERS - I would be hesitant to run them with more than around 280 pressure and maybe 5500 rpm. You can possibly sell them on Ehay for $100.00 and buy some nice scorpions, yeah!DOUBLE POST - I would edit/delete your text from the other post and just put "Double Thread", it will be easier for everyone.
hey shy shouldn't the push rods be shorter than stock if you make the head .050 shorter. i did this to a set of 455 6h heads about 7 years ago. i will check in the morning.
76 455/4spd TRANS AM69 GRAND PRIX 455/5SPD
Hello ROWSLEY;Yes shorter is correct. I corrected my TYPO, lol. Thanks.
Tim,welcome to the forum..A couple of thoughts.. a 455+30 with #96 heads shaved .050 will give you about 9.8-9.9:1 CR which is on the ragged edge of being to much for Pontiac Iron heads in regards to detonation problems with todays premium gas. If you deck the block you'll be well over 10:1.shaving .050 off the heads, while it can be done, will definitely give you areas to pay close attention to. One is the combined lift of your cam/rocker arms. I'd definitely do a valve clearence check on the pistons. Also, you'll loose some amount of "lift" you can have so depending on yor uexpected RPM range you could be limiting the ability of your motor to breath. A 455+.030 takes good amount of air.Yes, shaving the heads that much will defintely change the Rocker geometry so as the guys said, invest in a pushrod length checker and then order. When you order your rods, make sure you check a couple of things;1. That they are made in the USA2. Wall thickness of the rod. they come in varying wall thicknessess and depending on your spring pressure, you may opt for a thicker pushrod wall. I've seen them in .060", .080" and .120" thickness. I've gone with the "hardened" rods for added strength.You'll have to shave your intake an equal amount to the heads and you may find you have interference problems with the oil valley cover when you go to fit the intake. easy enough fix (grind a little on the edges of the pan where the intake is lowest) but something to be on the lookout for.Depending on your spring pressures, amount of lift and expected RPM range you might want to look into a lifter bore bracing kit. Where that might come into play is with open spring pressures of 300+ pounds (usually found with roller cam application) and RPM's over 5K.Just a couple of thoughts here..