bartmobile

Is there a way to tell if my engine had been bored out from a 330 to a 350 other than word of mouth

coppercutlass

The 330's had a diffrent bolt pattern for the flex plate, also the cam bank angle is diffrent from regular 350's .

TripDeuces

That's about an overbore of .120 or roughly 1/8 inch. The stock bore is 3.938. You'll have to measure the bore to be certain. So you should have a bore of roughly 4.057 if it were overbored which is the stock bore size of a 350 Olds engine. The 330 and the 350 share a common stroke of 3.385.
Other than physically measuring it or having one of those fancy Nascar cubic inch tools I know of no other way.

TripDeuces

I guess another method would be to get a bore scope and put it through a spark plug hole and see if the pistons are different from stock or if they even have a part number on the top. If no part number is visible and the pistons are not stock then all you know is they are larger but not by how much. Each .030 is equal to about 5 inches. That's how I arrived at .120. Assuming someone didn't use a stock 350 piston

bartmobile

Thanks I figured I would have to take apart to see. Not on my to do list right now. I am restoring a 1965 cutlass and I am almost ready to take off the body been a winter project for my son and I .can't do much here in barrie ontario cold and lots of snow can wait till spring.

OLD SKL 69

Welcome to CO, post some pics of your project when you get a chance.

joe_padavano

Let's back up. I assume the block casting number is for a 330? If so, is a previous owner telling you that it's been bored out that much?

bartmobile

bartmobile

Yes this is correct it is a 330 theperson I got it from said it was bored out

bartmobile

bartmobile

Love to but not quite sure go to do it been using my phone android not very good with these things computers and stuff. To old school I guess.