engine block casting numbers?

[daydreamer1252]

Is there a difference in the engine block casting numbers for a 2.5 and 3.0 GM 4cyl? (1984)

I only have the freshly rebuilt block with head (and new head gasket :redface attached (no other accessories or attachments to help determine the engine displacement) and original owner (not brilliant) has no clue of what I am talking about, HP, 3.0, 2.5 huh?. Trying to find out what I have without having to remove the head and destroy the new head gasket the rebuilder has so nicely installed and torqued. Any help is greatly appreciated, Thanks

 

[bomar76]

Re: engine block casting numbers?

As Don has told you it's pretty easy to MEASURE...
Hint:
Do it from the BOTTOM since you are all up in arms over the head gasket.....you can measure the bore and stroke, then do the math.

Addition:
If it was me I would pull the head to check out the head and cylinders and also who knows what this nameless mechanic may or may not have done.

 

[daydreamer1252]

Re: engine block casting numbers?

Thanks Bomar! I don't remember Don ever telling me anything! Yup, checked the records and not a one from Don not sure what you are talking about...? But I certainly respect his counsel! I know how to measure and derive the displacement of an engine, simple math. I am not sure how to measure around the crank and get any kind of accurate measurement on the bore size. Looks kind of tight in there!! Has been in past 4 cyl motors I have redone!! I am looking for a bore of about 4.25 if my math is right. I had asked earlier and got no reply whether the stroke of both motors was the same. I thought I remembered they were. However, if they are not, then if I know the correct stroke that would be child's play to measure. As far as taking it apart to check it out I am not concerned as it was done at one of Dallas' oldest and most respected shops. The tag is still on it. The money saved now will be needed in the refurb of this boat and motor.

 

[Bondo]

Re: engine block casting numbers?

Ayuh,.....

The 3.0l uses the 350's bore at 4" in diameter.......

The 2.5l is about 1/4" Smaller I believe......

as it was done at one of Dallas' oldest and most respected shops. The tag is still on it.

So call Them,+ Ask what it Is.......