I'm going to replace my valve seals soon, while I'm in there I was thinking of tossing in some new rocker arms. Are the gains worth it, if any?

On a 305? Not really, unless you're after minimumal gains.

get some 1.7 full rollers, now we're talkin!

i don't think you would feel any seat of the pants performance boost . i felt i had a little smoother running engine & better mileage . i did go with roller tips , comp cams 1416-16 . i plan on the same thing with my present car along with new ( stock ) valve springs . i'm not a racer , more of a cruiser & my car is a true daily driver . regardless of what you do when you change valve seals . make sure you clean sludge off of head & MAKE SURE drain passages at lwr. front & rear of cylinder heads are clear . they get sludged up and slow oil flow back to crankcase . i also like to use umbrella type seals on EACH valve intake & exhaust along with stem seals . many say its a waste of time . they are cheap and don't hurt anything . but thats just me , a little old school . good luck .

I'm not sure if it would get that part of the head but I've always run sea foam through my cars. I think it just needs stem seals, it only smokes on start up and never when actually driving.

WHAT ????

Sorry, I meant any gunk build up. I've always done my best to keep both of my vehicles running as clean as possible by running chevron gas and seafoaming them every oil change.



I've never actually torn into an engine, while I get the idea and mechanics of it and know I can easily do it, I just have never had to until now. So I don't know if stem seals are the same as valve seals or separate parts. Like I said it only smokes on start up after sitting over night and never smokes while driving.

if the valve covers are off , as they would be if you are changing valve seals . the drain passages are easy to access . i used a small diameter long screen door spring in a hand operated drill to clear them . many other things will work , skinny bottle brush , long screwdriver , air pressure , etc. . just clean-up the sludge so that the oil can drain back to the crankcase as it should . good luck .

My car felt alittle snappier and pulled alittle better up higher after I added some 1.6 roller tip comp rockers. I'd say do it.

i have some 1.6 fully roller 3/8 stud rockers would these work on factory 305 tbi heads?

should work just fine, just make sure they don't make contact with the baffles in the valve covers.

i don't have them but i feel i'd agree with robert here. that's for the roller tip type ones anyways.
btw, do the stock heads have 7/16 or 3/8 studs? and we need self-aligning ones, right?

3/8" stock.

yea self aligning unless u get some guidplates

if they do what should i do? can i cut out the baffles?

..Or get tall valve covers.

90Formula305 - Going to 1.6 rockers is about 6% more lift. IMO the biggest hp gain with stock heads and cam comes from the reduced friction vs factory rockers (assuming full rollers are used). You might feel a small SOP improvement, but nothing dramatic. Depending on how much you spend on parts, the cost to gain a few hp will be pretty high.

Having experience doing this mod, I advise you to look closely at how much clearance you end up with between the pushrods and the clearance holes on stock swirl port heads. 1.6's will move the top of the pushrod closer to the fulcrum to gain ratio, thus reducing clearance between the pushrod and the holes in the heads. Its very easy to put everything together and not see this. I had 1.6's on my car briefly until I realized my pushrods were rubbing on my heads. To fix this, the clearance holes need to be drilled out to at least .500. Still have the 1.6 rollers siting in the garage with just a few miles on them

What I did was just "crush" them with a pair of pliers to get them to work. It's pretty easy actually. You don't have to go crazy just aliitle squeeze works. As far as what Rock says I've had mine on my car for the last few years and not had any issue. I guess the best way to check is to put them on and crank the car over to see if they rub at all.

what are factory 1.5?

im going to throw on my 1.6 fully roller rockers and see what happends.