not sure if this is in the right forum but i have A 94 LT1 .30 over with CC306 cam...i was wondering if i could put 1.7 RR on with stock pushrods or do i need to have hardend ones...

 

What has been done to the heads? If the heads do not have 7/16 studs and guide plates then you need those before 1.7 rockers. Additionally guide plates will make the use of hardened pushrods necessary.

So I say hardened pushrods are mandatory. Stock pushrods are incredibly flimsy and flex at high RPM and spring pressure. The exact conditions your camshaft is designed to operate in.

 

would i need longer pushrods? or the same lenth?

 

Stock pushrod length should be okay unless the heads or block have been severely decked. I assume you have good valvesprings as well?

 

heads have been angle shaved .030...

 

You'll probably be okay with stock length but for about $15 you could buy a pushrod length checker and read up on how to determine the correct length. That'd be your best bet.

 

one more question.. i want to see what your round about on HP was...the car is .30 over, flat top pistons ARC rods, CC306 cam, heads are decked and shaved, intake is ported & polished, 52mm TB, cold air intake along with the aluminum elbow, MSD 6AL box and MSD full ignition, smog & AC delete, Hooker Comp. headers, hypertech chip with programer... exhaust is a y pipe into 4 1/2 pipe...what kind of HP would you say?

 

I would hate to insult you with a guess. But I would definitely recommend you to get a mail order or dyno tune and get rid of that Hypertech tune as soon as possible. Those tunes have been known to cause more harm than good in many cases.

 

Ill insult you with a guess, not meaning to be an insult, but probably not what you want to hear. You are probably not much more than a bolton only car, and it probably runs like **** with that worthless Hypertech tune. You need a real tune, not a Hypertech "one tune fits all" crap. So Ill guess 310rwhp. You have the potential for 360 on the rollers, but that cam is a dyno queen. The peak is high which is nice for bench racing and bragging rights, the area under the curve is shitty and produces lackluster 1/4 times. You would probably run the 1/4 in about the same time as a Hotcam car. Not to mention, if you are on the stock bottom end, and seem to not know much about these engines/engines in general based on your camshaft and tune selection, you are probably not spinning it where it wants to be spun to, around 6700rpm. Get a dyno tune, or at least a mail order tune, and a set of 4.10 gears, and it will drive much better, and be much faster.

What valvesprings are you running? I would make sure they are a GOOD dual spring if you are going to up the lift and ramp rate with 1.7 rockers. Too many behive failures around here lately on much smaller cams.

To your original question, anything over 6200rpm it is recommended to use Non Self Aligning rockers because Self Aligning rockers can float and spin off of the valve tip with the 2 tiny nubs on the end of the rocker. NSA rockers have a deeper pushrod cup and rely on the pushrod to keep them centered, so the pushrod must be centered at all times, so you need guideplates. If you run guideplates, the pushrod is constantly rubbing on them, and if they are not hardened, they will leave little metal shavings in your engine, so they MUST be hardened. Also, if you run guideplates, you need a longer base stem on your rocker studs, and if you already have to buy studs, might as well go with 7/16". The stud hole is 7/16 already, but the stock top is only 3/8. Upgrading to 7/16 will produce less flex below the rocker. So, you need 7/16 stud, NSA rockers, 7/16 ARP studs, guideplates, and hardened pushrods. Order a pushrod length checker first ($9), check the length, then order the pushrods.

 

I hear an ECHO Echo echo.. Must be good advice around

 

i bought the car, just trying to figure out the engine, iv heard they are very tricky motors...im an old school kinda guy, the LT1 setup and programers are not something im big on. but believe it or not the hypertech fried my ECU today when i was trying to reinstall the program and the 9V battery died and whiped everything out! what are yalls recomendations on programers?

 

google PCMforless or MadZ28 or Trifecta, there are a bunch of mail order tuners, all run about $200 and they will write you a custom tune for your mods.

Check the classifieds for a new PCM, should be between 40 and 80 bucks.