My 1970 442 455 motor was built as a gift to me and ended up with the low compression speed pro pistons. The cam was intentionally too much because I remembered driving the stock motor(1982) and couldn’t hook to save my life. Also I have to admit I love the idle sound. The car is mainly street but I do drag and autocross for fun when I can. I am considering changing to Rhoads style lifters because I need to reseal the intake. Cranes tech people say that their bleed down lifters require .100 longer pushrods. Rhoads says maybe, maybe not on pushrod change. Does anyone have experience with these or other similar lifters with stock valvetrain? The biggest issue I am trying to help is having to run so much initial timing that my eyes burn just getting near it when idling. I realize the best choice is a cam change but I don’t need to have “the best” I am looking for some noticeable improvement without changing too much.
Automatic switch pitch car with 3.42 and 235/70/15 drag radials.
Thanks

Cam is Crower 284HDP 108 LSA , adv. dur 288 int. 298 exh. @.50 is 228 int. 238 ex. Lift 464 int 482 exh.
I remember reading on the cam card that this cam grind already has 4 degrees adv. or I would just advance the cam to achieve some results first.

My first concern would be the burning of your eyes. Even with the wrong cam it shouldn’t be as bad as you’re describing.

To be fair , my last experience before putting the car away for winter was warming it up, idling to fill the transmission after installing it. The smell is pretty strong and soaks into clothes and hair immediately but not raw fuel. I have had the common quadrajet mod done to enrich the idle circuit and allow more air in, but in order to get it to idle in gear without dying and still not diesel when I shut it off, I have had to make the centrifical advance come in quick, as well as adjusting the vacuum advance to achieve the results. Before changing to the switch pitch I was running a higher stall (2500) converter and still having it die occasionally at stop lights. I knew from the start I was on the thin,ragged edge with this cam but truthfully that is what I wanted. Above idle the car performs beautifully and very smooth.

That’s a pretty mild girly-man camshaft, I’m sure you can tune the engine to perform better. If all you have done is start it and let it idle, take it out for a long drive and blow the carbon out of it. It’s probably loaded up. The cam isn’t any bigger than the 442 cams, and those cars idled and drove fine for a daily driver.

i agree with the fact that it should idle better but going from the stock 113lsa to a 108!sa will make a noticeable difference, especially if it wasn’t degreed properly in the first place.
My guess is the primary power piston is lifting as well. That’ll make it very difficult to tune the idle.

I appreciate any input, and I am always open to learn, but wasn’t trying to enter into a macho cam swinging contest . The 108 LSA adds to the challenge. The cam was installed “straight up” or dot to dot, which by manufacturers specs card is 4 degrees advanced already, otherwise I would be considering going that route. The valve train is stock. I have been able to “tune” the car to work fine, which at 4500 ft. elevation, with an automatic trans and power brakes is no small task. My questions were (1) asking if anyone had experience or advice on bleed down style lifters to help with vacuum at idle primarily, which would allow my tune to have less ignition advance, which would result in less hydrocarbons and less stinky.(2) if anyone had experience with either brand as to whether or not they both require a pushrod change. For what it’s worth if I do change the pushrods I am looking at the Smith Brothers with restrictiors, as no restrictiors were installed in the short block, which to me sounds like a better option for a mostly street driven motor but adding some protection for when I chose to “ blow the carbon out of it”. ��

Low compression Olds like yours like a ton of initial timing. Don’t know what that has to do with exhaust stink.

That is what I have experienced also. As I understand it, the timing advance is what increases the hydrocarbons which is the smell and what makes the eyes burn. Visine seems to be effective for that, but I’m really more interested if anyone has tried a set of bleed down lifters with a stock valvetrain and if the pushrods needed to be changed to a different length?