2 bolt or 4 bolt main in 73?

[trailblazr81]

Would a 73 K20 with 350 have 2 bolt or 4 bolt mains? My current stroker has a 2 bolt block bored .060 over, so Im looking for another block to use for my next rebuild.

 

[4X4HIGH]

There is no rhyme or reason for a 2 or 4 bolt block. Some got 2 bolt and some got 4 bolt. Also there is no definitive way of telling 2 or 4 bolt except to pull the pan.

 

[76zimmer]

anyones guess. If it has a 8" balancer it MIGHT have 4 bolt....other than that...drop the pan to be sure.

 

[dyeager535]

Don't get much info from folks on this, but what I've been able to gather so far is here:

http://dyeager535.topcities.com/suffix.html

Way too many engine codes out there for me to even get close to having them all, but so far still have not been proven wrong that suffix codes (when present) WILL indicate 2 or 4 bolt.

 

[76zimmer]

Don't get much info from folks on this, but what I've been able to gather so far is here:

http://dyeager535.topcities.com/suffix.html

Way too many engine codes out there for me to even get close to having them all, but so far still have not been proven wrong that suffix codes (when present) WILL indicate 2 or 4 bolt.

according to the list you have a 010-020 on there, is that the one under the timing cover. I heard those were higher nickel? content in the casting or something to that effect.


Thanks for posting those no.s

 

[dyeager535]

Getting off topic, but heres a thread discussing the 010/020 blocks. I asked for proof, sort of got it, but I'm still a bit skeptical. I've seen GM literature that is incorrect before, I would be completely sold if I saw plans for the blocks or ingredient listings from the foundry I guess.

http://coloradok5.com/forums/showthread.php?t=190270&highlight=010+020