ok i priced my head an the mods i want for it and at 975 bucks it scared me. so i was thinking of getting some roller rockers that i wouldent have to get new studs in my head. ive found some there stamped rockers 1.5 ratio and 3/8 stud do know if them would work or not the jegs part number is 778-66906

 

crane makes roller rockers specifically for the 300, kinda pricy, though. DONT get roller tipped, I assume that is what you are talking about with the "stamped" part. Spring for full rollers. I can't verify anything else I have heard about BBC rollers working, either. Maybe someone can say for certain.

 

when u say pricy what do u mean like how much

 

There isn't anything out there for the EFI 300. They use a pedestal mount rocker instead of a stud. I have been working on a 1.73 ratio rocker based on an early 70's 460 pedestal rocker. You have to modify the rocker stand to get them on. I've started on them, just havn't had time recently to do anything with it. There used to be a conversion kit for the pedestal 460 to a stud mount that used the stock mounting holes, but it won't work on a 300 because the 460 has splayed valves instead of inline. It could be made to work, but you would have to weld the adaptor plates together to keep them straight. Another thing I don't like about this design is that is basically has a 5/16" stud when you're done. That is the size of the hole the studs thread into, and I feel that's a little too small to be reliable.

 

The stud mounted roller rockers from Crane run ~ $270. Stamped refers to the process in which they're made. Stamped is similar to a forging process different from casting or billet - yet I never seen cast rockers - that would scare me.

 

i think a cast rocker would be more subject to failure...

Even a forged one would make me uneasy for some reason. I think i'd rather have a stamped steel rocker. Some weird gut feeling about that.....

 

All other things being equal, what kind of real world performance might one expect by converting to rollers... how many more horses would I have in the barn?

 

If you were to keep the same ratio rockers, i would say somewhere around 5-15hp. She's not revving too high anyways, so its not really going to get into it's max power range.

 

Most aluminum roller rockers meant for street use are cast. The high end big $$$ stuff is machined from extruded billet. I don't know of any that are forged of the top of my head, but there are probably some out there. Stamped is nothing like forged. A stamped rocker starts life as a flat piece of steel that is cold formed to its final shape. This introduces all kinds of internal stresses to the part and is good for neither strength, accuracy, consistency, or fatigue. The only thing a stamped rocker is good for is saving money. A forging is the same as a casting except the mold is subjected to very high pressures while the material is still in its molten form. If you really want a high perf. rocker stainless steel is the only way to go, but these are almost double the cost of a good aluminum rocker and offer no performance benefit on a real street engine, or on many race engines. There is no reason to fear a cast rocker unless you go beyond its limits. Most of them come with a disclaimer that they can't be used with cams over 0.550 lift, at more than 6500 rpm, or with valvespring forces over 350 lbs at peak lift.

 

high internal pressures created by forming caused by force just as in a stamping. You need to do your homework SS! I was wrong, the Crane gold roller rockers are die cast.

 

I found a head from a 83 block with studs and built in guide opening for the pushrods this head would allow the use of roller rockers from chev if they are long enough as the rockers on the head seem quite long (higher ratio) from the center to the valve, the studs are 3/8 , the whole thing is just like a chev but I don't no if they interchange any parts.This is the only head i"ve found like this all the others I've seen have the pedestals but it is obviously a factory part so there must be others.

 

You are the one who needs to do your homework., I've already done mine. In a forging there are minimal internal forces generated by the pressure. All the pressure does is produce a more dense and uniform grain structure in the metal. When a part is forged the pressure is exerted while the metal is in a nearly molten form. When it is stamped it is at room temperature. I already said that once, I guess it didn't sink in. There is a difference between applying pressure to a hot (near liquid) forging blank, forcing it to expand into the cavities of the dies, and stamping a piece of cold steel into a mold and stretching it around corners it doesn't want to go around.

 

SS is right, ever used a stamped steel wrench? Ideal for knuckle rash!!!

 

This is starting to sound a bit like the "which carb is best" arguments... or the HP/torque issue...

The 300,000+ mile stock rockers - are they cast or forged? I kind of like sticking with something that's been PROVEN - anybody have mileage results from the various types of rollers?

 

I used a Crane roller setup which is two roller(needle) bearings on a steel shaft which the rocker bolt goes through and the bearing takes the place of the fulcrum on the stock setup. I use synthetic oil and yet within 20K the shafts had signs of galling so I wouldn't recommend them also since you retain your old rocker no roller tip.