425 lifter angle WHAT?

Engine & Drivetrain

8 replies in this topic | 500 reads
442dreamer
Newbie
#1

I just bought a 1967 425 and it does not have the "drill mark" on the front ledge. I heard there are two different lifter angles such as 39 and 45 degree. What does a 455 have for a lifter angle.How do I know what I have? What is good and what is bad? Please help!

matt68F-85
Beginner
#2

All 455's are 39° cam bank angle. For that matter, all '68 and up Oldsmobile engines are 39° cam bank angle.

Nothing wrong with a 45° cam bank angle, just make sure the cam you use is ground for a 45° block.

Or you can open up the pushrod clearance holes in the heads and use a 39° cam.

If the engine is from a '66-'67 Toronado it should be a 39° cam bank angle with .921 diameter lifters.

442dreamer
Newbie
#3

Thanks for the reply. It came out of a 67 delta 88. How do you measure the cam bank angle? I need to know how to measure the angle,so I can order the correct cam.

matt68F-85
Beginner
#4

If it is for sure a '67 block, it is most likely a 39° cam bank angle.

check out this thread over on classicoldsmobile.com

https://classicoldsmobile.com/forums/tech-editors-desk/94057-425-cam-bank-angle-id.html

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matt68F-85
Beginner
#5

The post above is most likely correct. I don't know if it accurate in all cases.

Also look for a drill spot on the rib between the oil fill tube hole and the engine casting number D 389244.

Drill spot = 39°,no drill spot = 45°. you can also look on http://www.442.com/oldsfaq/oldsfaq.htm

Not sure all the info there is accurate or up to date. All of the blocks I have worked with were '68 and up so

no first hand experience with 45° blocks.

442dreamer
Newbie
#6

I just talked to Jr. at Olds Rocket Parts who is a great guy. He said all true67 manufactured 425 blocks were 39 degree. He said also if it had "C" heads on it, it is a 39 Degree for sure. Jr. said the 66 blocks that had 45 degree cam angle used a "B" head. The "B" head has a different push rod hole position in the head. He said the push rods wouldbind and not clear the push rod hole in the head correctly,if you had a 45 degree block and used a "C" head on it.

matt68F-85
Beginner
#7

That is why I said you could open up the pushrod holes.

allyolds68
Beginner
#8
442dreamer wrote:

I just talked to Jr. at Olds Rocket Parts who is a great guy. He said all true67 manufactured 425 blocks were 39 degree. He said also if it had "C" heads on it, it is a 39 Degree for sure. Jr. said the 66 blocks that had 45 degree cam angle used a "B" head. The "B" head has a different push rod hole position in the head. He said the push rods wouldbind and not clear the push rod hole in the head correctly,if you had a 45 degree block and used a "C" head on it.

Personally, I'd go to Bernard Mondello

matt68F-85
Beginner
#9

I wouldn't buy anything Oldsmobile coming from Paso Robles Ca.

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