pushrods,forged rocker supports, high strenght studs

[scootertrash]

Mike, if I could use your knowledge again, i've got some more questions. I've got a 07 fxstb with the factory 103 stage II kit on it. I'm gathering parts to up grade it a little. So far I've aquired a SERT, a SE 50mm throttle body, cnc ported HTCC heads, RBracing LSR 2-1 header and Jims roller rockers. I'm still looking at cams. You had kind of suggested a 257 or 258 of which the 258 sounds best to me. I'm open to other brands if you know of any others that I should look at. I had also considered the 260 but I was wondering if that might be alittle too much this small of a motor in a street bike that you don't want to have to rev the heck out of to leave every stoplight. I almost always ride one up,unless someone brakes and when I travel I travel light so extra weight isn't a issue for me.
My original question. At what point should I consider going to the forged rocker supports and high strength studs? Amy I at or past that point? ALso on pushrods, the "perfect fit" would seem to be the best, lower weight and less flex, if they are in fact perfect fit. What are your thoughts on this? If I go with adjustables do you have a favorite ?
Another question. On the cnc ported heads. SHould I blend the cnc machine work by hand, without changing the contour of the machine work? I've always polished the exhaust ports and put a rough, glass beaded or 80 grit sandpaper ,finish on the intake port and the chamber. Also on the throttle body the mouth of the body is rough cast. Would I benifit any by smoothing and polishing this and blending the sharp edge into the machined part of the throttle plate bore? ON the manifold side there places that look like they need cleaned up,not polished ,just cleaned up. As you can probably tell I'm ready to tear it down now, but I promised my buds I'd leave it alone till the end of summer. I've sold my shovel so this is the only thing I've got to ride so I have to leave it alone till cold weather. THanks for your help. A guy can get a real good education just reading the threads on this site.

[Mike]

Thanks for using our forum and the kind words. The 260 cams will require close to 11.0 compression to work well so the 258's look better for your build. The forged supports and HS studs are not bad things to install but we've never seen a stud fail (unless abused), the case will fail first (though the may not tend to stretch or spring as much as stock studs in hi-comp applications). The forged supports will help stablize the valve train but not so much until you get into really high valve spring pressures used with .750+ lift cams. No down side to using them other than added cost. I really like the Perfect Fits and try to use them whenever possible. The best adjustables out there are the Baisley tappereds with "May West" ball ends, but they are not quick installs. Here, rigidity is more important than weight so long as the valve spring are of good quality and properly packed.

We've not tried messing with the CNC heads (we use stock castings and Baisley Hi-Performance when going there) but anything that potentially improves air flow will help. So long as you do not remove a lot of material from the ports, the work your suggesting should be fine. Matching the manifold (and cleanup) will help, sometimes a lot, as well as the throttle body (if you get into the inside, that will help as well but is difficult). Roughing up slightly after polishing is good. Check valve to seat runnouts, if you can, and correct if needed, this will help seal and longevity.
Thanks, Mike

[scootertrash]

Mike , will those Jims roller rockers affect the selection of the "Perfect fit" pushrods? Also I read on one of the threads about different thickinesses of head gaskets to alter compression. Using the 258 cam and the pistons that harley makes for the HTCC heads, do you have a suggestion for gasket thickness? I think I saw that you had recommended .035 piston to head clearance. Is that correct? I have usually not gone closer than .040 on small block chevys, so I want to be sure that is what you ment. Is my valve to piston clearance going to be a issue with the 258 cam and these htcc piston? I'll probable clay them just for my own peice of mind anyway but it would be nice to know what to expect. Thanks again

[scootertrash]

I also forgot to ask about the clutch. The stage II kit came with a new spring. Am I going to need to upgrade my clutch when I do these changes?

[Mike]

The rockers themselves will not affect the pushrod lengths (stock geometry). The perfect fit choice will be based on the head decking, gasket thickness, valve stem lengths and cam base circle (assuming stock length cylinders). You have about +- .030 to play with here, but if you can get within +-.015 of the new lenght there's no worries. The 258's have base circle -.030 and would use the +.030 pushrod (18401-03) when used with the .045 gasket. going to the thinner .030 gasket only moves you .015 down and so the same pushrod would still be used. I like a quench of .030 but with the HTCC heads and pistons the .045 gasket would be the safe bet. Claying is always good to do but the HTCC pistons have very generous valve pockets and were designed to be used with cams having even higher TDC's in those heads.
Mike