Tell me about this 273 and tranny.

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I firmly believe it was the 273 HiPo that got the Chrysler engineers thinking about the 340...the idea didn't come from the 318 like most would believe
 
Dartswinger70 said:
I firmly believe it was the 273 HiPo that got the Chrysler engineers thinking about the 340...the idea didn't come from the 318 like most would believe
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I had often thought that. Mopar had been building HP engines for many years. The 273 started out as the first LA small block. With out anything else bigger in that same engine family, of course they would jack on up for more power. The 318 2 barrel was damn close to the same specs without all the HP technology. The 340 was the only engine they built in recent history that didn't start out as a 2 barrel. Yes, they used performance knowledge to build the 340 but not anything they already didn't know from decades past.
 
I always found it interesting that the first 340 heads and intake casting numbers start with 2531 which would indicate to me that they were thinking about a bigger cube HP small block seriously around 1965.
 
even if the motor is trash, the 4spd stuff is gold. i'd probably snap it up on the premise that i was gonna part the 273 and keep the 4 cog bits.

or part and sell everything to fund a nitro fueled turbo /6 with a jerico, in a rail.
 
It would give a stock 340 a run for sure, I had a couple, set up right it would make em look.
 
Professor Fate said:
Well, somebody's been into it- as @4spdragtop said, it's got 2 bbl. valve covers and a 4 bbl. manifold, so there's no outward sign of what truly lies inside. If it's really a 4 bbl. engine, then it's a '67 at the latest, a '65 at the earliest. If the 4 spd. has an output flange, it's a '65, if it's a slip yoke it's a '66-67. That's only if it was all born together. The motor mounts and brackets are early A, so '65 or '66, depending on the trans.
Oh, check the distributor- if it is dual points then it most likely is a 4 bbl. motor- single points most likely a 2 bbl. motor with a manifold swap. I *think* that looks like a dual point, but hard for me to tell.
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Sorry Professor Fate, I believe it is a single point, because all mine are iron for the duel point, this one appears aluminum, for a single point. The 65' intake is a low rise one and I also have one to compare with.
 
Swinger 340 said:
Sorry Professor Fate, I believe it is a single point, because all mine are iron for the duel point, this one appears aluminum, for a single point. The 65' intake is a low rise one and I also have one to compare with.
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Already addressed that four days ago.
Yes, the manifold is a factory low rise 4bbl.; which is why the rest of the components don't add up.
 
My guess is that it's a 2 barrel engine that someone put a 4 barrel intake on. Single point distributor and non HP valve covers for sure. The only way to confirm a HP engine is look at the pistons or carefully measure the cam. Those are the only 2 things that are different between a 2 barrel and a 4 barrel long block. Valve covers, intake, and distributor are all easily bolted on. It's pretty easy to tell if the heads and intake are 64-64 simply by pulling a intake bolt. The 64 and 65 bolts are 5/16" and the 66 and newer are 3/8". 1/2" and 9/16 bolt heads respectively. The early intake bolt holes are also drilled at a different than the 66 and newer LA intakes so they are not interchangeable without modification. Something else we can't see is the transmission output. the 64 and 65's will have a 4 bolt flange and the 66 and newer will have a splined slip yoke. Most of you guys know this stuff but some may not.
 
I am still trying to deal with this guy for the motor and Transmission.
I will keep up to date.
Thanks for the help so far FABO.
 
Have the seller clean the front of the block under the driver's side head. There are numbers stamped there that might shed some light.

Year
Displacement
HP or standard
 
I should have this motor and tranny here at my place Sunday and then we can see what we are dealing with. He confirmed that it does have the solid cam rockers on it as he has pulled the valve covers.
 
Moparlouie said:
All 273s had adjustable rockers until 68 I believe.
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Yes, 68 and 69 switched to hydraulic cam like the new 318 that was released in 68. The 318 LA replace the 318A which was the Poly 318. The old Poly had solid lifters as well.
 
toolmanmike said:
Yes, 68 and 69 switched to hydraulic cam like the new 318 that was released in 68. The 318 LA replace the 318A which was the Poly 318. The old Poly had solid lifters as well.
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The LA318 was introduced in 1967. There were some poly engines that had hydraulic lifters. I used to have a couple. I'm trying to remember what they came out of.... industrial or marine application probably.
 
cudamark said:
The LA318 was introduced in 1967. There were some poly engines that had hydraulic lifters. I used to have a couple. I'm trying to remember what they came out of.... industrial or marine application probably.
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Interesting. Did they still use the adjustable rockers? I couldn't imagine they would redesign rockers for a one or two year run.
 
cudamark said:
The LA318 was introduced in 1967. There were some poly engines that had hydraulic lifters. I used to have a couple. I'm trying to remember what they came out of.... industrial or marine application probably.
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Ah that's right. 66 was the last year for US built polys. Canada used them in 67.
 
toolmanmike said:
Interesting. Did they still use the adjustable rockers? I couldn't imagine they would redesign rockers for a one or two year run.
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Poly engines started back in the '50's. The rockers were non-adjustable on those two poly motors I had. I would guess that they were made for engines where access to removing valve covers was too restricted.
 
Distributor and starter have been replaced. 9/16 bolt head for intake bolts. No slip yoke tranny. Does have adjustable rockers.

It is in my shop floor now.

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I finally got to tearing the 273 down today and it is a Super Commando or what is left of one.

I am not sure if I will be able to salvage any lower end parts. I think it will depend on if I can get the balancer off.
 
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