boreing out a 250

[Anonymous]

what is the most cid you can get out of a 250 block?

I want to ues a 300 but it might not fit in a 1968 scout 800

i heard that the 300 breaths better than a 250 what can I do to fix that?
I am tryiung to get alote of low end torque and gas mileage

I want to turn a t19 and 3.50 rear and 33" tires over 75 miles an hour at 2500

 

[Anonymous]

The 250 is a thinwall casting, so you don't want to go over .040" if you don't absolutely have to, and it's certainly not with an extra 2 or 3 cubic inches... so you are stuck around 255 cubes with a .040" over.

Getting the 250 to breath is not easy or cheap. An Aussie cylinder head is an option, but a very pricy one. Pocket porting, a 3 angle valve job, and fitting a 2bbl carb directly to the intake is going to be the easiest and most cost effective method.

That should be plenty to do what you want it to. If you are going through with such a big swap, I would look twice at trying to get the 300 to fit though.

Lakeside, California... nice place. I used to live in El Cajon.

 

[Anonymous]

Im not to sure about the 250 blocks but i have read that you can go as much as .080 on a 200.