Going to V-8 - Swap K Member or Motor Mounts

[Hot Rod 63 Valiant]

Ok, the 63 Valiant I have has a slant 6 in it, I plan to be dropping a V8 in it. It will be either a 360 or 383. I have read that you have to swap in a K member out of a later model A body, then I have read that all I would need would be motor mounts. I also know I would have to get a steering arm for a V8 as well.

Can anyone with experience in these type of swaps share some light on the subject?

Thanks in advance,
Rob

 

[Slappy]

I changed my k-frame but I had a Demon that someone put in conversion mounts and had no issues. You might want to install v8 torsion bars while you are doing it.

 

[65 Dartman]

Early A (63-66) K's are the same for slant and V8s. You'll need either original V8 motor mounts or the conversion mounts as well as a 65-66 V8 center link. Don't forget minor things like a V8 radiator, torsion bars, beefier rear end, better brakes (at least 10 inch discs would be better). As I understand it, on the 63's some mods need to be done to the firewall in the distributor area as there's a bump-out where the distributor sits.

 

[Hot Rod 63 Valiant]

Thanks Slappy & Dartman! Good to hear I don't need to find a whole K member. The motor mounts & radiator are easy enough to find. Are there any sources besides for a wrecking yard to get the torsion bars & steering link? I may have the rear end covered, a buddy of mine says he may have one.

 

[C130 Chief]

ALL 63-66 A-body K-members are the same, and ALL 67 and later K-members WILL NOT FIT a 63-66 car. You need the following to swap a V8 into a 63:

64-66 A-body V8 engine mounts (original or Schumacher reproductions)
64-66 A-body V8 steering center link (all 63-66 steering arms are the same)
your radiator core support will not accept a typical 22" mopar V8 radiator, but can be modded with a saw.
the firewall on a 63 is different and will need to be dented slightly for distributor clearance (64-66 cars had a dimple pressed in)
Exhaust system, either use the awful 64-66 manifolds, moderately priced fenderwell headers, or really nice but expensive underchassis headers
throttle linkage, transmission linkage, driveshaft and such. A lot of this stuff can be adapted from a later car or use 64-66 parts.

 

[65 Dartman]

Since you're probably going to need to rebuilt the V8, why not rebuild a spare slant since it would replace what you already have? Maybe some O/S valves in a mildly ported and shaved head to bump up the compression. Add a set of headers. Instead of a 4 barrel, maybe something more exotic. Add a custom valve cover.

 

[Hot Rod 63 Valiant]

Now that's quite nifty Dartman! I could definitely see doing something like that on a 225, but the wife wants a V8 in it.

A good friend has a 383 & 727 tranny out of a Fury that he may be selling me, so that's probably what will end up in it. It's still up in the air at the moment rather it will be a 360 or a 383. I'd love to put a Hemi in it, but I can keep dreaming, lol

 

[C130 Chief]

Rethink the 383

 

[Hot Rod 63 Valiant]

Thanks for all the info Chief! Much appreciated! Not out of argument, but out of curiosity, why do you recommend rethinking the 383?

 

[Valiantsignet20]

383= bigger headache. Yes it will fit with a bit of persuasion and a lot of sheet metal massaging. The 360 with a 904 is a straight up, drop in and bolt up. With the 383 you're only gaining 23ci and about a 100 pounds of dead weight.


If I where doing it this is what I would do for a 360 auto.

Engine mounts from schumacher

64-6 273 manifold. (Headers run from $400 to $800.) You will have to grind the casting ear off the lower back drivers side head or make spacers for them to fit flush. I did both.

A 22 inch radiator will fit. You will have to drill 2 hole on the pass. side core support to bolt it in on that side. Drivers side already exsists. If you want to cut it out fine. The factory didn't in 64. Take note of what year water pump you use when selecting a rad. The newer aluminum style attaches on the pass side, the older cast iron on the driver side for the lower hose.

The /6 center link will work with the schumacher mounts.
(I can get my finger in between the pan and link)

The torsion bars can be bought from summit, jegs and mopar to name a few. I'd go with the .890 for better handling. All a body bars are interchangeable. The old drag racing trick is to leave the /6 bars for a softer suspension. Your call on that.

Use a 64-5 pushbutton 904. If you use a 64 you can use your existing ball and trunion driveshaft. 65 went to a slipyoke.
If you use a 65-up you'll need a drive shaft made. If not using a 64-5 use a 67 up with an after market shifter. Remember the 360 is an external balanced engine. The torque convertor must be balance with weights to the engine.

As far as rear ends go. Yes the 7 1/4 is weak. If you can get 8 3/4 or 8 1/4 go for it. If not it will work. Mine lasted 10 years behind a 360 and 30 years behind a 273 4 speed. You can't use sticky tires and do burn out competitions with it.

For throttle the easiest is one from a 64-6 v8. If not you can go with something like locar.

As far as brakes. At the very least split the system with a dual reservoir. If you don't mind the 4 on 5 bolt pattern use the scarebird disc conversion. If you want the 4.5 on 5 use the later model discs from a donor. If you have deep pockets you can go aftermarket with that too. Remember with a v8 you are adding weight and that auto won't engine brake very well. 9 inch drums burn up and fade fast in a panic stop from 70 mph.


Last but not least the firewall. 63 models had the wiper motor intruding into the bay. in 64 that bump was eliminated. I have seen 2 ways to deal with that. A hammer or use the 64 up wiper motor and cut the bump out.

Now. None of this is Gospel. And no one else's input is wrong. Take some time and search this forum. Guaranteed someone has already been there and done it...Many different ways. Learn from their mistakes and ease the pain on your wallet and sanity.

Feel free to PM me with any questions.

 

[C130 Chief]

Mostly because it was never offered in an early A-body so there are no factory parts to bolt it in with. Exhaust will be a real PITA as it's an even bigger engine in a small compartment. Heavier. 727 requires minor floor pan bashing. Newest one is 40 years old. etc...

If it were me I'd trade the 383 for a 5.9 Magnum. The extra 23 inches won't offset the extra 200-300 pounds and hassle of custom fabricating everything.

 

[Hot Rod 63 Valiant]

Guys, I really appreciate your input, you have definitely made up my mind as far as what motor to go with. Looks like we're going with the 360.

Thanks again,
Rob

 

[gtmopar]

I have a complete k member assembly from my v8 65 dart if you are interested. I just want to get it out of my garage. It's a 65 dart. All you need is torsion bars.

 

[Hot Rod 63 Valiant]

I have a complete k member assembly from my v8 65 dart if you are interested. I just want to get it out of my garage. It's a 65 dart. All you need is torsion bars.

I am definitely interested, thanks for the offer. I'd like to have one I can get powder coated & completely ready to just swap in. I'll shoot you a PM

 

[Hell_Fish]

Use a 64-5 pushbutton 904. If you use a 64 you can use your existing ball and trunion driveshaft. 65 went to a slipyoke.
If you use a 65-up you'll need a drive shaft made. If not using a 64-5 use a 67 up with an after market shifter. Remember the 360 is an external balanced engine. The torque convertor must be balance with weights to the engine.

65 904 is still a B&T yoke, but there was no push button in 65.

 

[C130 Chief]

But 65 was still cable shift.