Engine Size

[mneubecker]

I'm trying to determine if I have a 230 or 250. I finally got my 66 long step back from the bodyshop and was able to write down some numbers. They were hard to read even after several attempts at cleaning so they may not be 100% correct (especially the one on the flat pad by distributor.

Here's what I have - drivers side manifold 3859381 GM 17, passenger side near dipstick Con2 F227, flat pad by distributor 0625tf, passenger side between dipstick and distributor 3921968.

Can anyone tell me what engine size I have based on those numbers?

Also, from the drivers side kick panel I have paint code 510aa - I believe that's turquoise? The trim just says "std", I was hoping it would tell me the original color.

Thanks for your help.

[mneubecker]

Anyone?

[TimE]

On Inliners.org under casting #'s the 3921968 is listed as 230-250 from 1964-1976. That's all I found in few minutes. Try searching and see if you can come up with anything more detailed. Good luck.

I just thought, on my '66 250 there is a "4.1L" stamping (I don't recall exactly where right off) but that denotes a 250.

[low900rr]

Its a 250 if its a 66 and the numbers and letters by distributor are TF, last year for the 230 was 65.

[ol Curt]

I don't have reference in front of me to look up your code, but I'll dig thru some literature tonight. Actually, the 230 was still in production in 66...but 66 was the first year a 250 was available in the trucks. The stamping on the flat pad behind distributor is the one to use if you want to know compression ratios and such. But the one on the block will tell where it was made and the size. I don't find that block number listed anywhere.

[ol Curt]

Sorry, I wasn't reading it all. I was using your manifold numbers. Low90 is correct. I think the only way to tell the difference between the 230 and the 250 would be internals. I think the piston tops were different.

[low900rr]

the 230 wasnt offered in the 66's according to my literature

[ol Curt]

Point well taken. Mine was that it was available in cars and with it being 40 years old it would be hard to say it was original to the truck.

[mneubecker]

Thanks for all the info! I got the truck from my Grandfather and he had told me at one time that he had to put a new engine in it. I can't remember the details or how long he owned it before he made the switch but it sounds like that fact will make it more complicated to determine the size.

[ol Curt]

Well, if it helps, the parts are interchangeable. I think the only difference was one had domed pistons and the other didn't. I think the 250 had a little longer stroke. I would call it whatever you choose till you can tear it apart and go from there. Nobody else will be able to tell the difference either.

[TheDark1]

230 cid- 3.875 bore x 3.250 stroke
250 cid- 3.875 bore x 3.530 stroke