Alrighty here is the deal I am going to go 1-peice Comp Cams chromoly pushrods. Can i go 3/8" or should i stick with 5/16"? What is the advantages/disadvantages to each? The 20 dollar difference in price really doesn't mean much, since pushrods can be re-used, and plan to re-use them in my next motor buildup.

 

By the way has anyone ever checked the optimal pushrod length after 1.6RR install? Does it need to be any longer? I have heard from someone they needed a 7.300. How does that effect the top end or does it do nothing?

 

Defintely no need for the 3/8 pushrod. The stock length will be all you need for doing just a rocker swap. When you need to start worrying about the length is when the deck height of either the block or cylinder heads has been changed. By the way we offer the exact same 1pc chromoly pushrods as both Comp and Crane, but ours are a tad cheaper at $109 a set. Only difference is ours say Thunder Racing on them. Save a few bucks.

 

Unless you are running very high spring pressures you do not need 3/8" pr's. The added mass is a negative and a good set of 5/16" pr's will be stiff enough.

Rich

 

Yep Rich got it right with the spring pressure. Most of these springs that people run are fine with 5/16".

 

what about a gm847? would you need 3/8 rods for that cam because i know the spring pressure is pretty high

 

By high pressures they are refering to big solid roller cams springs that could reach 1000 lb, our HR cams have pressures around 300 lb.

 

Just out of curiousity, If I needed 3/8 inch rods. I'm assuming I would have to match the rockers and lifters. Would I have to do any machine work to the block.

 

No machine work. But you'd have to match the springs, rockers, lifters, cam core, and pushrods. It gets $$

 

ok...i think my setup will be fine with 5/16". Are new stock pushrods good enough? I have a brand new set of stock rods

 

Thanks guys. I didn't know how high of spring pressures the 5/16 were good to.


What about your shipping charge? I have other things i am buying. I am buying about $700 from summit and only have to pay 8.?? for a handling charge. Thanks for the heads-up though. Nice to have a Thunderracing guy on here now. You guys got a good set-up and nice to do business with and good customer service.

 

Probably run about $7 or $8 for shipping. The pushrods are currently in stock.