steve19

New person on here and i need a little help. I have a 66 olds 425 engine that has a 389244D engine and i'am looking for the place that the drill mark that might be there is. I read about it but i guess i'm looking in the wrong place so if anyone has a picture of it that would be great? Thanks
Steve.

442garage

I assume you are trying to determine if you have a 45 degree versus a 39 degree cam bank angle engine.

There are a couple of ways to check for cam bank angle, and if it is a Toro 425 block (probably applies to all blocks):

• Find the engine ID number/letter on the shelf behind the water pump, ahead of the intake, just above the timing chain. Now, at the RH [passenger] end of this shelf is an upright wall that runs fore-aft. This means the block is a big block.
• It should get fatter toward the front. Right near the top, in the fatter part, there should be a drill spot, at about a 45 degree angle [parallel to the even-bank head bolt holes] and just barely drilled into the wall or rib, until the diameter got to about 3/8". If that drill spot is there, then the block is almost w/o a doubt a 39-degree cam block. Every 1966 to 1967 Toro 425 and 1966 to 1967 442 400 engine I have seen so far had this drill spot and had a 39 degree cam bank angle.

Basically, the way it worked out was that if the early (pre 1968) big block had 0.921 lifters, it was an advanced [for the time] 39-degree block, and if it had the normal 0.842 lifters, it was an old 45 degree block. Anyhow, the presence of the drill spot on a pre-1968 big block means a 39 degree block and heads. Easy to spot, too.

steve19

Thanks for that info will clean that area tomorrow and see if i can find it. Thanks Steve

geckonz08

If the heads are B --and they should be and the casting no on the heads is 389395 and you have the "drill spot" I am 99% sure you have a toro 425 with the large valves in the head
mike

steve19

Mike checked the passenger head today and it looks like a V or N 52 9583 it's hard to see and i don't see any drill mark. The guy i got the car from says the engine came out of a 66 olds 98 it has the original red paint still on it and the air cleaner is a red and orange colors with super rocket ultra high compression premium fuel. Steve

steve19

Sorry mike forgot to tell you that they are B heads it's tough to get old. This engine runs preety good for what it is pretty much stock with just a set of headers
it' in a 68 chevelle 4 door so it' pretty much a sleeper has a posi rear and i think it has 3.55 rear gears or 3.73 not sure. Steve

geckonz08

use search facility and look at posting by raymondh36965 titled "425 cam bank angle ".Norm has posted some good pics of where to find the drill spot
mike