jd 70 bore

[John179]

i am ready to bore out my jd 70 gas and am wonder how far i can bore it out before i have to sleeve and cement. any help would be great.

 

[Drew]

If you are trying to gain a bunch of power from a simple overbore, you are wasting your time. I know people have bored a 70G block to 6.125, or +.250", but you may scrap a few otherwise good blocks before you get a good one at that bore.

You MIGHT gain 5hp by going from 5.875" to 6.125". There are easier ways to gain that much or more power and not needlessly take life out of the block. If you have to bore the block to straighten up the cylinders, bore it the minimum needed and quit.

 

[John179]

i plan on strokeing as well but i dont want to go to big because i still want integrity in my block

 

[jd b puller]

6" would be a good place to stop. Not sure what the "norm" is for stroking. Imagine it is around 9.75", maybe a little more.

A PowerBlock would get you 6.5" and can be bored a little, I've heard of a handfull of guys going to 6.75".

 

[Hot Rod A]

Another option you could look into if you"re really after more cubes without hardblocking, depending on how much you"re a fan of the 70 head, is to swap the block out with a "G" block and head. You can bore a G block out to 6.375 pretty safely and have solid integrity yet, and then if you go with a Murphy"s G head and duplex manifold, you can still run your 2 barrel carb, and it would make for a decent setup.

 

[Anonymous-0]

would you email me i have a few questions for you. thanks ricky