Hopefully the answer to this one will be easy and relatively straight forward. Recently took my 103 from stock to Stage 2. SE Hi-flow A/C, Klock Werks exhaust, 255 cams w/ SE tapered adj. push rods. The added lift of the cam has increased the top end noise quite a bit.

So, I've been reading through the forum and it seems that it's fairly common for the increased lift of non-stock cams to increase the ticking sound. I have decided that I'm going to open the top end, inspect everything, and give the Rockouts a try. For $15 plus a couple of gaskets it seems like a pretty affordable thing to try and the reviews have all been positive.

Since I will have it open anyway I'm considering going back to the stock length solid push rods. I've already researched and found that the stock rods can be used with the 255 cams as long as your heads are stock, which mine are.

What I'm hoping someone can tell me is if going back to the stock solid rods will screw up the tune? The adjustable rods were set to the recommended 15 flats when it was tuned, if that info helps.

TIA for any info on this.

 

Shouldn't affect tune, but why?

 

Why to which part?

 

The pushrods aren't going to affect your tune.
If you look in the P&A book, the same size pushrods fit the stock, SE203. SE204, SE211, SE253, SE254E and SE255 cams.
No matter what cam you run.


I added the solid (non-adjustable) SE Pro Perfect Fit Pushrods when I add the SE255 cam.
I wanted them because they're stiffer and lighter and I was already in the engine.
Solid pushrods so I wouldn't have to worry about adjustments.

 

Are the perfect fits the same lengths or are those the ones that are +.030?

 

As long as all the pushrods you are swapping out are the length, then nothing should change.

 

I was figuring that the MoCo says to set the adjustable rods to 15 flats so the length and therefore the pre-load on the lifters would be the same, or nearly the same, as the stock push rods. But not knowing for sure I wanted to ask.

 

I used PN 18400-03 (original length.)
Changed from stock cam to the SE255.

 

Cool, thanks for the info. The adjustable rods are working fine right now but I figured since I'm opening the top I can eliminate a possible point of failure down the road.

 

No reason to think the adjustables would fail in installed correctly. Set them .140 deep from zero lash and your top end will definitely be quieter than stock pushrods.