I bought this cam/lifters for my 305 > http://store.summitracing.com/partde...4&autoview=sku

When I unpacked it, I compared it with the old cam and lifters and noted some differences:












As you can see, there are some diferences between the two camshafts and the lifters..."pushrods slots"? so I'm worried because the rockers will go down a lot compared to before, does it matter? the pushrods length is 7.755 (197mm), should I swap to bigger ones to compensate the diferences?

Thank you for reading.
(Again, sorry for the mistakes, my english is all rusty)

 

From those measurements, it looks like the pushrods should be .172" longer than the old ones from the motor. That looks like they just used a smaller base circle for the cam, which is fine other than the pushrod length. You could put together one exhaust and one intake with the lifters/pushrods/rockers, and see if it is far off. Best way I've seen is use a permanent marker on the top of the valve to mark it, then as the rocker makes its travel to full lift and close it will show where on the valve it touches. Idealy you want the marker to show the rocker hitting the valve right in the center. Other than that, I see that the old cam had .328" lift where the new one has .470.

 

Ok,

I've been looking for Pushrods .172" longer than the originals, I found those
http://store.summitracing.com/partde...6&autoview=sku
Good? bad? thank you.



Here's a pick of the actual pushrods (5/16)

 

Just saw a screw up, the diameter of the two cams is different by .172", but the pushrod will only see half of that difference. You're looking for .086" longer, sorry bout that. Just anything that's a 5/16" rod 7.850" long should be fine. Like I said though, assemble an intake and exhaust and see if it turns out to be fine. I'm betting it'll still be pretty centered on the valve.