What motor do I have 273 or 318?

I just picked up a 1967 small block motor. Chevy guy I bought it from said he took it out of his friends 67 Barracuda. They think its a 318. The casting number on the block is 2806030-273-4 cast on 4-7-67. The number stamped on the front of the block under the head is C 318. I thought the casting number on the side of the block had the motor displacement in the number which is 273 but on the front the stamped number is 318. What makes it more confusing is the motor has the 273 adjustable rockers with the correct heads and date codes. How can I find out what I have?

since you can't make a 318 out of a 273 casting, I'm gonna say 273.

Measure the bore. 3.625 vs 3.91

Being 67 and adjustable rockers, I'd say 273. But who knows, maybe they just put the wrong numbers on the side or front since 67 was the first year for the LA 318, but not in a Barracuda I think. 67-68-69 where the last years for the A-body 273s. At least it's got the good steel crank. Only one way to tell....

After looking at those rockers again, they look added, retainers are too big for the springs and they too look bigger than stock, then the aluminum intake too. Somebody's been changing parts. What's the head numbers?

Wrong number on the side, lol. Listen to what you said. Everything you point out, except the numbers on the side, can easily be changed after it left the factory. The casting numbers can't.

measure the bores, anything else is BS.

Had a 67 Fury one owner since new that had a 318 Poly from factory.IIRC it was a real early build.Paid 75 bucks for it because timing jumped.New chain and my brther drove it for 3 years.Rocky

The head numbers are 2658920 with the correct 67 date code. The motor had a LD4b manifold and Mallory Dual Point dist added but the cam is original. Can the adjustable rockers be used with the hydraulic lifters and cam?

Its supposed to be a running motor so I really don't want to pull it apart to measure the bores unless I have to.

Go with the casting number, that's a 273 that someone stamped 318 on the front.

yes but you likely will need shorter pushrods (mockup & see what you have for preload/threads showing under rocker tip) which might not be as critical on a daily driver but see what you got & go from there. EDIT cup/ball end rods like the OE solid lifter pushrods. MORE EDIT after some brief thought, very likely you will need shorter ball/cup pushrods.

What makes you think it has a hydraulic cam?

Since it IS a 273 block, it IS a 273 and would have solid lifters and adjustable rockers stock. If the cam is stock as you say then the rockers and pushrods should be correct.just remember it needs lash not preload.

The casting numbers tell the story, you have a 273. I have had several 273's. Up until 1968 they all came with solid cams and adjustable rockers. The 68 engine I have now, came with a hydraulic cam and stamped steel rockers like the 318's.

2 barrel engines were solid lifter also?

Kevin

No. 273's went up to 1969, had a 69 Dart convertible with one in it, two barrel only in 68 and 69.

My 65 Satilite has the 273-2 bbl, solid lifters

When I purchased my Challenger someone install a 273 in it fun little motor. Solid cam 10.5/1 piston. Just be aware 67 and pprior had a smaller crack hub for the torque converter later so if swapping trans take measurements first

As I said ALL 273 engines, 2bbl and 4bbl, were solid lifter engines until 1968. 68 and 69 came with hydraulic cams and stamped steel rockers like the 318.

As said definitely a 273 short block. that is a new one on me, stamping the front dr side of the 273 block with "318" & they kept the 273 solid lifter stuff. Any evidence of a restamping there?

Does not look like it was restamped.

Assembly line workers have their off days too (all I can think of).

Exactly.

R.

Ok I took off the oil pan and it has a windage tray and someone installed a Milodon oil pump, so someone was working on the engine. While I had the pan off I measured the cylinder and it was approximatly 3.625 so Im guessing a 273 motor someone restamped.

I wonder why anyone would restamp a 318 or 273 block. They are both basically throwaway blocks. As in, I have been given three 318s.

IMHO it is much more likely that whoever was doing the stamping at the factory goofed.

R.

Most likely it was done by a dealership as a warranty replacement. They most likely installed the 273 and stamped 318 on the front to fool the owner.