250 inline identification

[aboz]

Can anybody help me I.D. a 250 inline that I'm thinking of putting in my truck? the block code is:3877178C. The guy selling it had had it in a '63 Nova. My current six came from a 1970 Nova and mates with a four bolt pattern Saginaw 3 speed column shift. This block has a six bolt pattern. Does anyone know if this swap out will work? Thanks

[Shaky]

I'm not following you. Usually the four bolts of the Saginaw are where it bolts to the bell housing - right?

Are the six holes on the back of the block, like this?:

[aboz]

You are exactly right! The guy with the engine must have thought I was talking about the bell housing bolt pattern as well. If you happen to know how I can decipher the engine block code I would be interested to know what year it is. He says its a 250 from the 70's. I think all Chevy 250's were discontinued around '76.

[Shaky]

I think the 250 went into the '80s (the 292 went into the early '90s). In the early-to-mid '70s the 250 got an integral intake manifold (intake and head were cast as one unit). Does yours have that?

This place says it's either a 230 or a 250:

http://www.adchevy.com/tools/casting...submit=Lookup#

[aboz]

Its definitely a separate intake and exhaust. It has a Clifford intake and what seems to be the factory exhaust. Thank you much for the info. My instincts tell me this engine should fit and the pictures of it look exactly like mine.

[Heater63]

as you just learned, the casting # doesnt help much in these engines. However, there is another number cast there, that has the year of production, but they used it both decades!! So if it is an 5, you could have a 65 or a 75!

Pull a spark plug, turn it over to tdc and see if you can tell what piston top shape is.
230 used a flat top with "eyebrow" valve reliefs
250 used a piston with a sunken area in the shape of a D

[Heater63]

and, yes, this block is the same in cars and trucks, the bellhousing pattern is the exact same L6/ small block/ big block.

You will have no problems swapping it in.

[aboz]

Every car or truck guy around here asks me why I don't just drop a V-8 in it. Not an economical option for a daily driver. Gettin' about 16-18 mpg with a Holley 2bbl 350 cfm. Gonna' try switching to an old Rochester Dualjet. I understand that they can be tuned for fuel efficiency far better than my Holley. I love these old straight sixes! Easy to work on by yourself, even when pulling out a transmission for a quick weekend rebuild! Thanks for the info.