is there any difference in pushrods lengths for a 86 305 non-roller and a 88 305 roller? i believe both motors use self aligning rockers

now i want to pick up some comp cams magnum 1.6 ratio roller
tip rockers, and they recommend changing pushrods, which isnt a bad idea, i want to get the pushrod length checking tool and measure it up, but i have world products s/r torquer 305 heads for 87+ there arent no guide plates, so i am assuming i use the comp cams self aligning ones, what is the standard size pushrod so i can order the length checker?

i believe the heads have a max lift of .560

my cam is a .452/.465 with 1.5's with 1.6's i should have .482/.496

so i should be okay with the valve springs correct?

 

You should be ok as far as springs. I would be wary with any spring that came on the head from the factory. There are many stories of factory springs going bad. Even on top of the line hedas such as AFR.

As far as pushrod difference, the pushrods for the flat tappets are going to be longer considering as how the flat tappets are shorter than the roller tappets. the stock pushrod diameter is 5/16."

And a note about the heads, i dont think that the fact that they are 87-up has to do with the self aligning rockers (though they might, buti doubt it - im not an expert on aftermarket heads). But i do know that when most companies say 87-up for their heads, they are refering to the intake manifold bolting pattern. in 87, they changed it up a bit and the 2 center bolts on the intake manifold were angled differently than the rest. Im pretty sure that is what they mean when they say they offer heads for pre-86 and 87-up. You got the heads that were drilled for the later style intake with the center bolts angled differently

 

i think the differance between roller and flat cam push rods is .4, whatever it is it's quite a bit so they don't interchange. push rods are 3/8" length of roller push rods are 7.3 and flat cams are 7.7 i think but not 100% sure.

 

IIRC its something like 7.125 for roller and 7.800 for flat tappet.

 

I would replace the springs for anything other then a stock buildup.