273 -318 swap information needed

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If you're keeping the stock '65 transmission, you will need the crank bushing to reduce the hole size to the small converter button. Depending on the year of the 318, you may have to modify the engine mount brackets. 318's with all four bracket ears on both sides shouldn't be a problem, but, some only have 3 ears on a side, and they're usually a different 3 ears than the 273. I'd convert the front end of the engine to the '65 parts just to keep from having to modify radiator and fan stuff. I'd put a new timing chain set in there while I was at it. Most 318 balancers are the same size as the 273, so, either swap it to the 273 balancer or use the 318 one if they match up sizewise. The 318 balancer from '72 and later had an even bolt pattern for the pulley. The earlier ones have one offset bolt hole (like the 273). You can slot the hole either way depending on which balancer you use. As for the timing mark, just cut the 273 TDC slot to the 318 balancer and highlight it with paint, if you decide to use it. There again, depending on the year of the 318, starting in the mid 70's the heads started to have smog ports drilled into them below the exhaust port. You'll need to plug them to use the 273 manifolds. The intake would depend on which choices you have with the 318 you get. The '65 intake won't fit on a 318. If you want the stock look, get an intake off a '66 or '67 model. That way you can use your stock carb, choke, and kickdown linkage without having to modify anything. If you get a 2bbl 318, get it with all the intake parts including the carb, choke, and air cleaner. You should be able to tranfer kickdown linkage from your 273 to the 318. If you go 4bbl. all that would have to be changed (check for hood clearance before getting an aftermarket intake). Another area that might need to swapped over is the oil pan, dipstick and tube, and oil pickup depending on year and what the 318 was in. If it were me, I'd also put a new set of brass freeze plugs in it, if they don't already have them. I'm sure I'm probably forgetting something, but, that's all I can think of now.
Thanks for all the great information!
 
Since you don't yet have an engine, a 360 drops right in there too. With the only
additional hiccup
being the one engine bracket, which is easy to solve.
 
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Since you don't yet have an engine, a 360 drops right in there too. With the only additional hiccup being the one engine bracket, which is easy to solve.
Well, also that the 360 is externally balanced. An aftermarket 360 external-balance flexplate would allow you to run a neutral-balance torque converter, but you would have to run a 360 damper up front. Couldn't use the one from the 273. Would have to run a 360 oil pan, too, but that should fit a 65 Barracuda OK.

A 340 would drop right in, but they are hard to find these days (I'm old enough to remember when they were easy to find in junkyards, but that was a long time ago.)
 
Well, also that the 360 is externally balanced. An aftermarket 360 external-balance flexplate would allow you to run a neutral-balance torque converter, but you would have to run a 360 damper up front. Couldn't use the one from the 273. Would have to run a 360 oil pan, too, but that should fit a 65 Barracuda OK.


A 340 would drop right in, but they are hard to find these days (I'm old enough to remember when they were easy to find in junkyards, but that was a long time ago.)
Thanks for the great information
 
Well, also that the 360 is externally balanced. An aftermarket 360 external-balance flexplate would allow you to run a neutral-balance torque converter, but you would have to run a 360 damper up front. Couldn't use the one from the 273. Would have to run a 360 oil pan, too, but that should fit a 65 Barracuda OK.

A 340 would drop right in, but they are hard to find these days (I'm old enough to remember when they were easy to find in junkyards, but that was a long time ago.)

Also the 360 uses a different oil pan. It has the big main seal front and rear. I have a 360 in my 63 Valiant where a /6 used to be. I may need a different center link for to clear the oil pan.
 
Since you don't yet have an engine, a 360 drops right in there too. With the only additional hiccup being the one engine bracket, which is easy to solve.
Quite a bit more than just an engine mount bracket to put a 360 in a '65 A-body. Already mentioned is the external balance issue and oil pan (some pans need to be messaged a bit with a hammer). depending on the balancer, some pulleys don't like the external weight. Exhaust system is a whole nother bag of worms.
 
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