OLDS Stock length SBO pushrods

[rfpowerdude]

What is the stock length for pushrods in a 403? Same as a 350 from '68 on I am guessing. I've read 8.234". Just want to check with the resident experts.

 

[69hurstolds]

Depends on the year. Some have .375" diameter ball ends. Some .3125" ball ends. I think this is also the reason they used different rocker arm part numbers later in life. Never actually researched it.

According to GM parts information, push rods for "modern" Olds V8s are all over the place as far as lengths and years and engine sizes. 64 was interesting that it has shorter pushrods for 442 engine than the non-442 330 V8. The 215 V8s prior used 1/4" spaghetti push rods!!!!

Anyway...

68-79 350 and 403 used the same push rods. Ball end size was .3125". They were 8-17/64", or 8.265" long rods.

80-81 260, 350R, and 307 and factory 350N diesels used 8.265" push rods with bulbous .375" ball ends. Obviously flat tappet 307s through 85 also used the same 8.265" rods.

It's something like 7.718" for stock 307 roller push rods and goodwrench diesel 5.7.

CLEAR AS MUD.

 

[rfpowerdude]

Thanks Mike, that does help a lot.

 

[olds307 and 403]

Great info from 69hurstolds as always. Yeah, I almost forgot about the early 80's ball end pushrods. I remember putting on my 83 5A 307 heads on the 76 Olds 350 for my 78 Chebby 1/2 ton. The push rods have to match the rocker arms or expect binding or excessive play. I was going to mention the 7.7" length, wasn't 100% sure, for the stock roller cam motors but who knows if the aftermarket .842" retro fit roller lifters are close to the same.