Though I've been messing with classic cars for a while now, this is my first time doing a rebuild or even pulling an engine. I spent quite a bit of time reading old threads and followed the advice of a lot of knowledgeable members. Well the engine is out and I will start taking it apart soon to see where I'm at. What I do know about the motor:

-It's a 389244D casting. C heads tell me it's a '67
-The stamp on the front of the passenger side head is R100151 which tells me it's a 10.25:1 high compression non-Toro motor. It is painted bronze now, but it is red underneath.
-It does have 0.842 lifters; I have yet to definitively determine the cam angle
-The only known additions to this motor are an 8qt oil pan, high volume oil pump, mini high-torque starter, Performer intake, and headers.

At the moment, I do not have any new performance parts picked out, or know to what extent I will have parts machined. I'm going to get it all apart first, figure out what I have, and then start doing my research...My end goal is to have an aggressive street car. The car has 4.10 gears in a Chevy 12 bolt and 2400 stall. Transmission is a TH350.

I'm looking for any input and thoughts as I move forward. Thanks!

 

Here are some pictures before I tear into it. Do the lifters usually sit un-centered on the cam lobes? Something I haven’t noticed before..

 

The lifter offset is an engineering design that causes them to rotate on the camshaft lobes.

 

You're in luck. I'll have an off the shelf performance piston available for the 425 the first of next month.
And I have hyd roller cams available for that lifter/bank angle as well. Let me know if I can be of any help.
Best of luck in your build!

 

You may have a 45 degree cam angle there as the lifters appear to be centered in their bores in the block. Here is a picture of 2 425 blocks. I think the 39 degree cam angle lifters are not centered in the block casting bores. Someone can back me up on this please.

 

I’ve seen the same image floating around the forum also. This one says the 39 degree angle lifters are centered.

Another method I came across in an older thread: https://classicoldsmobile.com/forums...ank-angle.html

I placed the straightedge on the head intake surface along side a push rod and it’s clear there is more space between the straightedge and the push rod the close it gets to the head. See the picture below. Am I correct in saying the cam bank angle is 39 degrees given the centered lifter bores and pushrod-to-straightedge measurement?

 

Great. I will get in touch with you when I get to that point. Thanks!

 

Good to know. Thank you

 

I got the engine apart and the bottom end appears to be in great shape. The heads are pretty gunked up though. Almost all of the valve stem seals are broken and pieces of plastic were all over the place. The heads will be going out to the machine shop soon.

I’m going to switch back to a stock size oil pan since the 8qt is a little beat up. Plus it makes it pretty much impossible to pull the engine and transmission together with that huge oil pan getting caught on the crossmember.

 

Well plans changed and the 425 was swapped with a 455. I got the motor and trans back in this week. I’ll hopefully have it running in a few days. Thanks to Mark (cutlassefi) for helping me out with a cam. This was my first time doing any sort of engine swap/rebuild. Everything I had questions about was covered in detail on this site. I’m not sure I could have done it (or at least without a lot of headaches) without CO.

 

IMHO you would have been more than happy with the short stroke of the 425. But it was your call, I would have kept the 425 and built it. 425's with that casting number are 39 deg cam angle.

 

I still have the 425 and plan on building it in the future. It came down to cost on this one and it was cheaper for me to go this route. I just have to find something to put the 425 in now..

 

Hey we just rebuilt the same block number 425 last year. Feel free to browse the thread to see if there's any info that might be helpful to you!



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