1.7 rockers on stock engine?

Hi!
I have a 69 Camaro SS engine in my 58.
Its the "GM 300hp" 350ci with 10:1 and the 041 heads.Original camshaft.
As i want a bit more topend i thinking about getting it quick with 1.7 rockers.

Will there be a piston to valve problem?
Do i need hardend pushrods?


thanks a ton,
Ollie

 

You will not have piston to valve problems if it is a stock cam.

The problem you will have is the pushrods will not clear the guide slot in the head. The pushrod seat in the rocker is moved towards the pivot point and the pushrod will bind on the slot towards the pivot.

It is common to use a "Louis" tool to lengthen the slot for 1.6 rockers, but I doubt that a 1.7 would clear.

Big Block Chevy rockers are 1.7 but use a 7/16 stud and are physically too long

 

Compared to a 1.5 rocker that usually comes on a SBC, you should get about .050 more lift. That is a substantial increase. I would definitely check a few clearances before just firing it up.

 

I wouldn't do it.The 1.7s are basically a full race item on small blocks.The only thing you're going to do is wear out your valvetrain components quickly not to mention possibly binding or breaking something.Cams and lifters are $200 or less.That's the route I'd choose.Lots more power and you'd know you did it right.

 

Even with a 1.7 rocker your lift would be less than .450. Stock springs will handle that. Stock pistons will clear over .500 lift.

 

Ok,i'll use the 1.6ers.Don't wanna risk my fresh engine.
I have a comp cams 274H layin around.Might be the better solution.

Thanks folks!
Ollie

 

Do you think i'll have slot issues with 1.6ers and the stock cam,Bob?

Ollie

 

I did....changed back to stockers