[pharmd]

Is the stock rocker with trunion upgrade adequate, or is their a real concern necessitating I run a full roller?

My engine guy says anything over .600 lift and 6000rpm needs full roller (he is a Ford guy). He also is concerned about spring pressures. Additionally he suggests that once preload is set with pushrod length if the valves need to be adjusted in a different spot it would be nearly impossible with the limited travel lifters. He says with aluminum block/heads preload changes a lot when it gets hot.

I have too much money in the setup as is, and really don't want to have to buy yet another set of rockers. The motor will be used for HPDE, autox, and some daily driving.

Anyone know the limits on these stock rockers with the upgrade?

Any help appreciated!

[dailydriver]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

[pharmd]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

Just ordered the Yella Terra Adjustable shaft mounts. So lets see what happens. My engine builder basically said he wouldn't put out this quality of motor with stock rockers on it. So I will have a set of rockers with brand new trunion upgrade up for sale soon!

[1qwikbird]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

Just ordered the Yella Terra Adjustable shaft mounts. So lets see what happens. My engine builder basically said he wouldn't put out this quality of motor with stock rockers on it. So I will have a set of rockers with brand new trunion upgrade up for sale soon!

I would hold off on selling the stockers until you get the motor on the dyno and see if you experience any kind of valve train instability in the upper RPMs. Seems like some guys with aftermarket setups have valve float or flutter in the upper RPM, as seen on the dyno sheet, then go back to stock rockers and the problem goes away. Its not universal, but I'd hate to see you sell off stuff only to buy it back later.

FWIW I have a set of TFS heads as well (215's bought directly through Brian Tooley with all the goodies), and I went through exactly what you are going through now. I have Comp Pro Magnums on the motor, but it hasn't been run yet. Fingers crossed and a set of stockers with the trunion upgrade on standby, just in case. I did have a stocker spill its guts, so I've been down that road as well. At one point, TFS recommended a full roller with their heads, but I believe that was tied to the guide wear issue more than valvetrain stability, but looking at their website, they seem to have backed off that stance and if you look at the rockers they sell, they only offer upgraded stockers or a crower shaft system for the LSX crowd, coincidence?


Good Luck either way.