65 Belvedere daily driver's slant 6 died, need help picking/swapping new engine.

I am the proud owner of a 1965 Belvedere II which has been my daily driver for the last 6 months.
The car has been very reliable, but recently my 225 Slant 6 (automatic, not manual) died. 2 of the cylinders have almost no compression, but the rest of the engine should be pretty solid according to my very trusty mechanic. The engine still starts and runs, but stalls when the car is idling in drive, and it goes without saying that it really isn't running well.

I found this '69 Belvedere Slant 6 for cheap, and I figure it would be easy to salvage the good parts off of my current engine to get back on the road quick and cheap.
The Slant 6: https://pittsburgh.craigslist.org/pts/5023320146.html

BUT, I'd really rather put a bigger engine in if I'm gonna be putting in a new one, and I found a complete 318 and 727 transmission out of a '71 Cuda that is really appealing...but I'm also on a tight-ish budget, and I'd like to get back on the road within a week or two at most and make use of as many of my original parts as possible.
The 318: http://youngstown.craigslist.org/pts/5018889760.html

How hard on me and my wallet would the 225 to 318 swap be? As far as my research tells, if I can manage to find a V8 K frame from 62-65 then everything should bolt up with little or no custom work. Is that true? I've been having trouble finding good info for this swap, and I don't want to buy the 318 and find out that I'm in over my head budget or ability wise. (fyi, I am 23, and my dad and I are pretty experienced mechanics, he has a few engine swaps under his belt but we're both fairly new to 60's MOPAR)

Long story short, if I wanted to put a complete matching 318 and 727 out of a '71 'Cuda into my 1965 Slant 6 Belvedere what other parts would I need and what modifications would be required? Should I go for the 318 or stick to the 225?

Oh, and if you've got a better engine option or parts sitting around you want to sell me, I'm all ears ;)

My Plymouth:

I would stick with the /6. Its not that the swap is hard, but if you need it back on the road asap, the 6 is going to do that. The swap isnt hard, but its a bunch of little things that will add up to not done in 2 weeks. Unless you have all day every day to work on it. Once back on the road and running well, then start gathering parts to do the swap. You will run into little issues like throttle cable length and drive shaft lenght, and slip yoke size. Minor wiring length issues and coolant hoses. Exhaust system as well

I agree with everything Hemi said, besides I like the / as mentioned below in fine print!

They didn't put 318 engines in 'cuda models. Only Barracudas. I'm suspect of that ad, show me the stampings and VIN numbers
I have a V8 k-frame for an early B-body for sale

dunno bout where it came from,cause poster above me is right,no cudas with 318s.
but what i did notice is it has the engine rebuild inna can...
look at the hoses,they just sprayed Everything.....
except under the headers where you can still see the Rusty block!
lol..

You will need to change the front K frame (which means taking the entire front suspension off and putting it on the V-8 k frame). Also, your trans shifter linkage only fits 65 and earlier transmissions (cable shift). If you replace the /6 engine, it will need to be a Pre 68 as the trans is different (crank flange/torque converter). Would be easier and cheaper to fix the six. Could be something as simple as a blown head gasket.

i thought schumachers carried Swap mounts so you dont have to change /6 k frames?
also,
short term thoughts.
put a 6 back in for now.
fix the one you have,which isnt knocking? and could be a simple teardown and rebuild/regasket.
are the 2 cyls that have low compression right Next to each other?

long term thoughts
buy a running 383/auto combo,everyone goes for the 440s but a good 383 will put a smile on your face all day every day.
plus they are usually dirt cheap because> everyone wants the 440! lol.

I am swapping out a slant six auto for a big block in a 65 Belvedere. Trust me, NO ONE makes anything to allow you to keep the /6 K frame, not even Schumachers. (They do have the motor mounts for the V-8 to V-8 K member).
I threw a rod in my current OE slant six and found out that the 65's were unique, as are the pre-68 automatics. I was going to swap a perfectly good 79 Volare slant six in until I could finish my big block. You can use a later /6 auto combo but you will need to get an aftermarket floor shifter.
OH, one other thing....
65 was also the last year for the CV joint on the drive shaft of passenger cars. As a result, some 65 cars have a flange/CV joint in the front and back, some have it front only, and some have regular Universal joints front and back. My 65 Fury has front and rear U-joints but my Belvedere has a front CV joint and a rear U-joint.
I am just trying to give you a heads up on any snags you can run into, not trying to dissuade you from doing a swap.
I can't wait to get that big block in my car and go racing.

I've run into the same exact situation. Sticking with the slant 6 for now, although I rebuilt and modified it alot. Eventually going to a BB swap down the road. Already have the early k-member, 383 block and other parts.

I would try and fix the original. Could just be a headgasket. Also, does this /6 have solid lifters? When were they last adjusted? Loose, worn timing chain?

If it still runs I would start with the motor you have.

Fix the slant 6. Half the parts you take off your k member when you swap it out will need replaced more than likely and it will run into a huge headache not to mention exhaust, wiring etc.

Probably just needs a valve job broski.

The bottom ends are solid.

Update: I scrapped the slant 6 and replaced it with a newer slant 6 with 40k miles on it that had been built up a bit by its previous owner. Got it for only $200 since it had no intake or exhaust when I got to it (used to have a 4 barrel and an offenhauser intake), used the old parts from my original 6. Ended up doing an HEI conversion, which gave it a little more grunt. I must be crazy because the day after I finished the swap in late October I drove from Pittsburgh to Seattle in it, pretty much no problems. Lived there for a few months, my stock muffler finally fell off so I put on a Thrush Turbo muffler. Love the sound: https://youtu.be/9IM5kqLrAeY

Recently moved back to Pittsburgh (shipped the car this time), got a few minor issues but mostly things are good. Just set my best mileage record, 31.5 mpg highway on 93 octane. Pretty sure my carb needs rebuilt or adjusted (will stall in 10-30 seconds ish when car is off of choke, in drive and not moving), and I've got the car going to my local driveshaft shop for a balance/maybe new U or CV joints (car has a pulsing vibration at 60-65mph and I just had my tires/wheels checked). Beyond that, my valve cover has a slow leak, got a nice chrome one and a new gasket on the way, and I have some rust issues on the front fenders that need attended to; looking for replacement fenders or a stellar body man to patch them up before the snow and salt shows up, on the right side the rust has eaten through to the hood hinge and one of the bolts of the hinge is now free floating.

Looking to switch from 10 in drums up front to 11 in drums with the Brake in a box kit and replace the original master cyllinder with a new dual chamber unit once my current issues are settled. Thanks for all the advice, you all helped me a ton!

Is it just me, but do I see a V8 emblem, on your first picture of the 65' you posted ?

Yeah, I've been told that Ma Mopar put those on all the Belvedere II's that year as part of the fancy trim package, regardless of what was under the hood. Hard to find info to back that up though, idk.

If you're really on a budget, shipping a 318 or 225 across the country is probably not a good idea.
I see 318s advertised for a couple hundred bucks several times a year within 100 miles of where I live.

...and no, they didn't put v8 emblems on slant six cars. pretty specific about emblem use.
In later years (67) Six got nothing, 273 2 barrel got v8, and the rest got the displacement.
On the hood ornament anyway.

YY1 said:

If you're really on a budget, shipping a 318 or 225 across the country is probably not a good idea.
I see 318s advertised for a couple hundred bucks several times a year within 100 miles of where I live.

...and no, they didn't put v8 emblems on slant six cars. pretty specific about emblem use.
In later years (67) Six got nothing, 273 2 barrel got v8, and the rest got the displacement.
On the hood ornament anyway.

Click to expand...

Shipping an engine? I shipped my whole car when I moved back to Pittsburgh, but that's about all the shipping I talked about. Only cost me $1200, which was only a little more than the cost of driving it and way cheaper than trying to buy another 60's mopar in good shape. I'm sticking with the 6 until further notice, so this is kinda moot. Did you mean the 318 in Youngstown? That's like 80 miles away from me tops.

The V8 badge in question is on the fender, not the hood, and it was there when I bought the car, I guess in the last 50 years someone swapped the fender. Car is a 65, btw.

Sounds good.