Yeah... Eight years later... My problem is I was sold an engine as being a 230, and it has (as far as I can tell) flat top pistons with valve reliefs, but...the stamped number on the pad behind the distributor is F0604TA (which I believe tells me it's a 250) and it has a HEI distributor (which I believe only came on 250s). Also, the head takes tapered-seat spark plugs, which I believe makes it a 250 head. And...it has been rebuilt, so who knows what's in there?
F = Flint Michigan 0604 = June 4th TA 67 truck 250. c can be either 230 or 2250 as the bore is the same but the stroke is different. The HEI can be swapped around a**** any late but wasn't available until the 1975 Model. The rebuild shop tag says that the distributor was put in by who ever installed it in the vehicle it was bought for. The tag just means it went through a rebuilder shop and is .030 over with a 10-10 crank. The paint color rather looks like what was usually on 230 engines with orange on 250 as far as chevy went. It is also close to pontiac color but the chart I found only went to 76. Paint color could have been the rebuild shops "shop color" I have run into that on rebuilder shop engines that painted every engine that left the shop their color rather than the correct color for the engine. I stumbled on this and from it it says that the engine left the factory as a 67 truck 250.
Thanks for the reply, Mr48chev. Most evidence does appear to point toward it being a 250. But the flat top pistons... I was thinking maybe someone put 230 pistons in it, but I don't think that's possible due to wrist pin height. Maybe the engine rebuilder found some flat top pistons that would work in a 250 and used them to increase compression ratio...? I might be able to find the phone number of the guy I bought the engine from. As I recall, he pulled it out of his '67 truck. I got the impression it wasn't the original engine for the truck, but maybe it was. Loppy posted this above, which also shows this to be a 250.
I'm not betting on anything anymore. I've had a 194 and a 250 in my 48 along with a 283 and 350. Putting well over 100K on the 250 on top off the 94 K it had when I put it in the 48. Worn out to the point it didn't have enough compression to start. This time it gets a 292 with a bag of tricks and goodies. I don't remember all the where and what for's but the go fast brigade has mixed and matched internal pieces on these sixes to come up with some interesting combinations using off the shelf parts.
I seem to recall the 250 had the lower pulleys made on the balancer, the 230 the pulleys were a separate piece like the sbc, etc. Someone earlier said 350 pistons, but I think it was actually 283.
Yes, you are correct, 283 pistons will fit a 230. I have a seized up 230 with Forged 283 pistons in it. The numbers stamped into the tops of the pistons showed up as forged TRW pistons according to the internet. Why on earth anyone would rebuild a 230 for a 1964 C-10 with forged pistons is beyond me.
In fact, aren't the 230 pistons THE SAME as the 283 pistons right from the factory? But if that's the case, 283 pistons wouldn't fit in a 250. But since a stroked 283 is a 307, maybe the 307 pistons fit in a 250...?
looking closer, the Chevy parts book lists the 230 and 283 pistons as being the same part, but not the 250 and 307
a 307 has the same 3.250 stroke as a 327. A 250 has a 3.530 stroke. I snagged the following page of this thread from a few years ago https://www.jalopyjournal.com/forum/threads/194-to-250.1210725/ SBC bore and stroke for comparison.
The 230 and 250 have the same bore but different stroke, so if the 283 piston fits the 230 it should fit the 250. Shane
Interesting... I spent quite a bit of time on the net last night. One of the things I learned was the 307 has the same bore AND stroke as the 230, so I would have thought they'd have used the 307 pistons.
Nice. I just spent some hours last night creating a chart with much of this info. But this is better. It shows rod length and other relevant info. And, btw, I see the 194 through the 250 all have the same rod length. That means the difference in stroke is made up with wrist pin height (aka piston compression height). And it shows the 250 to be an odd ball as far as stroke and wrist pin height.
All this data brings up something I found interesting... The bore and stroke of the: 194 shows to be 3.563 x 3.250 which corresponds closely with 3 9/16 x 3 1/4 215 ................... 3.750 x 3.250 .................................................... 3 3/4 x 3 1/4 230 ................... 3.875 x 3.250 .................................................... 3 7/8 x 3 1/4 250 ................... 3.875 x 3.530 .................................................... 3 7/8 x 3 ?/? The closest standard fraction I can come up with for the 250 stroke is 17/32, but that comes out to .53125. Rounded to the nearest thousandth, it would be .531, not .530. It's just something I found that made me go, "huh." I wonder if the engines were designed in fractional inches, but the machine shop used decimal inches, or they were designed with decimal inches, and they chose to make them close to fractional inches.
Different engines were designed differently. Most chevys use fractions, but there are a few decimal strokes such as the 250 you discovered, the 3.48 stroke on several small block V8s, and the 3.76 big block stroke. Buick used .400 a few times, and there are others a**** all the different engines. It's arbitrary, so don't read too much into it.
Looking at this info some more, I see almost all of the gen 1 V8s have 5.7" rods, as do the shorter I6s. Since the 283 has a 3" stroke, the 230 has a 3.25" stroke, but they use the same piston, I think that tells us the deck height of the I6s is 1/4" taller than the V8s.
that sound right...almost. Perhaps it's 1/8" different, since half the stroke is above the crank center line, and half is below?
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