do shaft mount roller rockers really yield a net gain in hp versus stock pedestal mount, non-rollers? by net gain i mean at the rear wheels. when I dis-assembled my 5.9 the stock rockers felt and sounded so loose. I know it would make me "feel" better for them to not be so loose feeling and sounding, but would the hp increase be worth the money? Thanks

 

Yes, there is a significant difference.

 

Aww, man! dont tease me. Numbers! I need numbers!

 

I would go with no. Dyno numbers...you might get a few HP, but $/HP, I dont think youd be happy.

On a race motor, diff story...but for a somewhat stocker, esp a 3.9...wait, where is the 5.9 coming from? Swap?

 

as always, depends on what else you do. Stock tune the rockers wont do anything. Take advantage with tuner and/or exhaust/intake and they're worth something. It's equiv to a cam swap, without the cam swap.

 

Oh yeah. I forgot to mention that I am swapping the stock 3.9 for the same year 5.9. Sorry. The block is in the machine shop getting bored .040 over, zero decked, align honed, squared, blah, blah, blah. I'm replacing the stock heads with cast iron RHS X heads with 2.02 intakes and 1.62 exhaust. I'm still deliberating over the cam because I want good low end torque without sacrificing too much at the middle and top end, maybe a range of 1000-5000rpm. I love the sound of a V8 screaming but dont really want to go with solid lifters and all the changes that would have to be made. I think an edelbrock F1 Airgap intake with a 53mm throttle body will make the power i want. but those are the plans, anyway, for the engine. so would the roller rockers really make an appreciable difference in the hp with this setup?

 

IMO it'd be more reliable and stronger...esp if you're gonna have a high seat pressure.

I'm assuming you're going to have a tuner as well?

 

Are you implying that simply swapping rockers, from stock to rollers is equivalent to changing the actual cams? I hope you're not serious.
You can maybe get higher lift rockers, but, they still keep the time the stock cam has, and would only allow a bit more air/fuel in; or exhaust out. That is unless you get the roller set off to advance/retard the lobe on the stock cam.

It really sounds like you should talk to a motor shop vimnjicki. Or, find someone who has a full set up, similar to what you want to achieve. You should really design your exepectations, then build the motor to them. You can put $12K in great parts into an engine, and still have a POS. I would seriously consider having everything laid out. If you have all your numbers, which you seem to have around 60% of them, call Comp, or a few other cam guys. They can grind a cam to meet your needs. Balance low end, and high end. Make a plan, and stick to it. Don't piece things in to attemt to make it better, just cause there are shinier parts or someone somewhere gained 'mad speed' from a perceived upgrade.
Oh yea, what are you doing with the truck? DD? Track? P-Wagon? ha!

As always, beware the internet.

 

I dont think magnethead said that.

To me anything that can reduce wear and improve efficiency is a plus if you can afford the price stock are fine the roller rockers if a quality design are more efficient. Improved or increased power maybe not but an improvement over stock yes.

You must question the quality of any aftermarket product and the dependability of that product some are great at what they offer and some are questionable and you are better off not buying it.

Always ask about a product from people that have used it if it’s worth it to use or avoid it at all costs like the plague.

 

That's all I meant, not that it's the same as a cam change, but can make the engine "think" there was a minor cam change.