Slant 6 to small block 318 on 63 Valiant

[Jerold]

I was wondering if anyone can tell me how hard it would be to swap out a 225 slant 6 with a 318 v8? And what changes I will have to make to the frame if any.
Thanks!

[Stoga]

Actually, it's fairly straightforward. The K-member is the same on all A-bodies from 1960 to 66, so all you'll need is a set of 273 v8 brackets and mounts, No modifications to the K-frame needed at all. If you could find a used up 1964-66 v8 Dart-Valiant or Barracuda parts car, you could swap everything over, but you would be ahead finding an 8 3/4 axle for an A body, cause the 7 1/4 used behind the sixes just won't hold up behind a V8.

[dschumers]

You may want to measure the width of the engine bay. I've been told that the pre-'64 cars were too narrow for a V-8 without a lot of cutting. Don't know if it's true or not, but it came from a guy with 2 '62 Valiants.

[Stoga]

I had a 62, they narrow toward the front, but further back they are the same. 63 body is same as 64 to 66. Big problem with the 60 to 62's is probably the heater box sticking out on the passenger side.

[Doctor Dodge]

With all the parts from a 64-66 A-Body, this swap can be done.

By far the biggest issue with using a small block Mopar V8 in a 63 A-Body chassis is that the 63's firewall has a big bump in it for the wiper motor. (this bump was removed in 64)
The bump will need some trimming / denting to make room for the SB V8's rear mounted distributor & cap.

Other body / chassis limitations include the 19 inch radiator opening and the near flat steering center link, which will hit the SB V8 oil pan. (A 66 and later center link has a deeper "drop" in it so swap one on to get around the pan)

The other hard parts to locate these days are the 64-66, 273 exhaust manifolds and engine mount brackets. (67 on up are different) Everything else is pretty straight forward.
DD

[Jerold]

What about adding headers will this cause even more problems or would it make it easier?
Jerold

[Doctor Dodge]

Unless there is something new now on the market, the only headers I have seen for this combo were "fenderwell outlet". (Cut open the inner fenderwells)
Needless to say, that adds more problems.
DD

[chrisb53]

dont worry about headers. pick up some 273 exaust manifolds they act like headers and will fit between the inner fenders.

[delshin]

Sorry kind of new to this. I am working on a project car. 63 v-200 sedan, 4 dr auto. Just got done indtalling a 89 van 360 engine, 727 trans, 8-1/4 rear, disc brakes. problems I had are as follows: 727 housing larger than old 904 ( i would opt fpr a 904 next time); I had to cut the tunnel to clear the 727; sb fits tight but goes right in; I got a set of headers from Spitefire, Mr. Harold Johnson 479-474-1551 (nice guy) ( tri-Y type headers, cannot use power steering, gets real close to fender well on right side, looks and sounds great, had to do some minor mods to help with installation, slight problem I just had - I just fired the motor up to break in the cam and I noticed some anti freeze dripping from back of motor, looked like was coming from head, but it was leaking from the header bolt , I did not know that for the heads I had that the 1 st and last holes are threaded through to the water jacket); hump in fire wall for wiper had to be modified to clear distributor cap; have to modify wiper linkage now; cut open radiator opening to squeeze in 26 wide radiator; radiator to water pump pulley clearance only 2-1/2 inch so needed electric fans; using a B&M shifter so cable route close to headers( I need to install some heat shields); my centerlink was stock but it had about a 1 inch drop, this cleared the new passenger car oil pan that is needed; also needed the right angle filter adapter, installed with filter toward forward end of car to clear headers; got mounts (engine and trans) from Schumacher in seattle; stocj starter fits also but I found a mini from a wrecked dodge ram; relocated battery to give me some space in the engine compartment.
Fun project for me. I you got any advice for me let me know. Hope this helps

[wrenchhead_2002]

unless you go with mopar manifolds you will run into a lot of cutting the biggest problem with ever installing v8's in a- bodies was the common fact that the headers just dont fit the steering boxes get in the way but there are a few aftermarket header companies that make v8 conversion headers whci with slight modifications and minimal cutting will fit

[delshin]

This is my first project with a mopar, but I have been fortunate with the lead on the spitefire headers from Mr. Harold Johnson. They are tri-y type headers. You are right that the fit is tight. I did not have to do any cutting but, the passenger side header is only about 3/4" away from the fender well; I removed the exhaust manifold studs on both ends of the right side head so I could fit the headers into the space; had to install the right angle filter adapter; to install the driver side header I need to remove my steering coupling; a power steering gear box will not fit with the headers installed (Mr. johnson informed me of that). I am installing heat shields for the gas and the brake lines and brake proportioning valve. I may need more. I am only using 2" exhaust pipes I fabricated to clear the torsion bars. Maybe later a muffler shop may be able to fit some 2-1/4 " pipes. Other than the slight modifications, the headers are a nice fit.
Is it true that the 67 and later A bodies are wider in the engine bay?

[Slant Cecil]

The '67 and later A-bodies are at least a couple of inchs wider. I never measured the difference but a big block fits in a '67-up easier than a small block fits in '66-down. The early A-bodies are the lighest of all. A '63 Valiant slant/904 with no options is maybe 350 lbs lighter (or more) than a '76 Duster slant/904 with no options. These are great cars for hot rodded slant 6s. V-8s have few choises for header slection. Either the Spitfires (which are maybe better than manifolds) or the more effecient fenderwell design (but holes in the inner fenders weaken the car and there is tire to header interference). Stock '64-'66 273 manifolds are restritive and not so easy to locate. What I'm saying? Jerold, keep the slant six in and modify the heck out of it and have something a little different.

Cecil