I'm doing a rebuild/freshen up to a 95 351W and am wondering about the use of 1.7 roller rockers. Basically I want to run the stock cam and swap the stock rockers to 1.7 ratio roller units. I have done some searching but can't find a defintie answer because it seems everyone else using them has them on a stroker or an engine that isn't comparable to mine. Basically I just don't want the SD to end up hunting for idle as my truck is primarily a trail rig and I can't have an erratic idle on the rocks lol. The engine I'm using will still have the stock E7 heads with new valve seals and the valves cut. I may also do some mild gasket match porting and polishing.

Another question I have is with the 1.7RR I should be able to use stock length pushrods correct? Also what about valve spring rate, are the stock springs ok with the added lift?

The info I have researched seems to indicate that it should be fine as far as the SD goes in being able to control idle but I'm still not sure.

Thanks in advance for the help.

 

my understanding is you will need new pushrods to run 1.7 rockers.

 

I replaced the stock rockers with 1.7RR on my stock 1987 5.0HO with no other changes. Initially, there were some tapping from the lifters due to the new positions the rockers were pushing them to, but they went away by themselves. The engine is running just fine now. Unless you drastically shaved your heads or block, you should not need new pushrods. Of course, since the new 1.7RR did not change the engine enough to upset the stock SD computer, I wonder just how much performance they're adding to the engine.

If you've also made modifications that allow the stock heads to flow much better, you may run into some issues. You may be able to deal with minor issues by installing an adjustable fuel pressure regulator, and increasing the fuel pressure slightly.

 

Thanks for the responses. I think I'm going to go ahead and do the 1.7RR just becasue it's already gonna be apart, roller rockers are better than stock with less friction and 1.7 ratio will open the valves more. There is the question of how much performance gain do you really get out of them but there has to be some.

If I do any port work to my heads it will be to take the hump/bump out of the exhuast side and just clean up the intake side a bit along with a gasket match. Nothing crazy just enough to make me feel better and also to gain a bit of experience with head work. Been reading up a bunch on DIYporting.com

I don't really wanna change the cam as these roller cams are pretty much the best setup for what I do with the truck although I would love to have that rough idle that sounds so badass while the truck is idling over the rocks. Any great experiences from a cam swap and which cam did you use?

From the reading I've done the 1.7RR allow a good idle but just let the engine breathe a bit deeper at the higher RPM. Obviously the main restriction is the intakes but for the money the RR are a good investment IMO

This started out as a super super low budget build but as usual there seems to be a snowball effect starting. I gotta stop it before it's out of control. I'd love to build a 408 stroker but that's DEFINITELY not in the cashflow for awhile.

 

The rockers will allow the motor to breath better at all rpms, and that's good because the 5.8 can really use it. The intake isn't as bad as you think but it does have one glaring restriction that you could address while you have the die grinder out, that is the port exits in the lower where they meet the heads. The ports narrow down in both dimensions in the last inch or so before the gasket surface and it doesn't take much work to remove this, just be carefull not to over do it and not leave enough material for good gasket seating. In this case you don't want to gasket match you just want to port match the exits to the intake openings on the heads.

 

That's really good to know. I had just been reading on the head work so far and hadn't gotten to the intakes yet. I know the right thing to do would be to buy aftermarket intakes but if I can get a slight performance bump out of the stock ones I'll be fine with that on this motor.

I was always happy with the power the motor in the truck made, well when it had lower miles anyhow. I just figure while it' apart I may as well do some "free" upgrades.

Any suggestions on the rockers? I was gonna go with proform pedastal mount from JEGS