Pushrods 5 16 or 3 8

[Eskedal]

I have a Gen 2 Viper and 3/8 push rods do not fit in a stock cylinder head.

Will a Trend push rods in 5/16 080 work as good as 3/8 with stock 708 camshaft?

Any tips here?

[ViperTony]

FWIW I used tapered push rods from Viper Specialty in my Gen2. They are double-tapered 5/16" on the ends and 3/8" in the middle. http://viperspecialtyperformance.com/catalog/product_info.php/cPath/22_28/products_id/108

[Eskedal]

Sorry, I have double tapered 5/16 on ends and 3/8 in the middle, but they do not fit. Se pictures

39481

[ViperTony]

Sorry I only see one picture and it looks as if the pushrod fits....when you say it doesn't fit do you mean its not fitting through the actual head and seating into the lifter? I'd contact Dan Lesser at Viper Specialty for guidance.

[ellowviper]

I used Trend 3/8 for years on my GEN-II with no problems...on TD roller rockers. You have to get the right length...duh. Now on GEN-IV/V heads, I had to go back to Trend 5/16 pushrods since you don't have clearance to run anything greater in diameter (even after doing the required mod).

[Eskedal]

Yes, pushrod is in contact with the intake side of the cylinder head. Maybe 2mm off, pushrods need to be in center of valverocker bolt. I must order Trend 5/16 to get it right.

@ellowviper
Are you sure that you have clearance enough on stock gen 2 heads?

39486

[Dan Cragin]

Those 5/16 .080 pushrods will be fine.

[ellowviper]

Yes, pushrod is in contact with the intake side of the cylinder head. Maybe 2mm off, pushrods need to be in center of valverocker bolt. I must order Trend 5/16 to get it right.

@ellowviper
Are you sure that you have clearance enough on stock gen 2 heads?

39486
Yes Sir. They were pretty stout pushrods recommended by Greg Good as part of my solid roller rocker cam. Worked well.

[Eskedal]

I have grinded in the head to make more clearance for 3/8 pushrods. No problem now :)

[d124716]

odd question BUT, has anyone run into an issue with stock pushrods being too close to the intake port of the head?

[Aevus]

Now on GEN-IV/V heads, I had to go back to Trend 5/16 pushrods since you don't have clearance to run anything greater in diameter (even after doing the required mod).

thanks for the thread revival I didnt know 5/16 was the max possible on gen 4/5

[d124716]

Ops... probably worth mentioning that I am inquiring about Gen 2 (2000 model) seems as my Cylinder 10 pushrods are awfully close to the head... was wondering if during operation and when heated and expanded a contact might be possible. Is there any general rule of thumb clearance that there should be between the pushrod and "surroundings" to compensate for pushrod flex and expansion of surroundings?

[Dan Cragin]

The 3/8ths pushrods hit the intake runner on all the Gen 1's. I use the 5/16 .080 wall pushrods on the Gen 1-2 cars.

[d124716]

The 3/8ths pushrods hit the intake runner on all the Gen 1's. I use the 5/16 .080 wall pushrods on the Gen 1-2 cars.

I have stock pushrods. Have you ever had those be too close to the intake?

[Dan Cragin]

They have clearance, but get close with even the stock pushrods on a Gen 1.

[laney487]

hey dan are you saying if i do the roller rocker upgrade on my gen 1 that i dont buy those 3/8 pushrods with it? because they wont fit and they hit the intake runner? not trying to hijack i just know your the master of reason!

[GTS Dean]

That's what the man is telling everyone. Use 5/16" 0.080" wall pushrods on your Gen1 & 2 builds with stock heads.

[laney487]

got it.. im going to do headers and exhaust on my gen 1 first then roller rocker upgrade was next in mind but wont be till next year.. so this is good info to know!