/6 to 318 V8 swap issues

While searching the web, I have seen some postings related to this /6 to 318 V8 swap. I am hoping to consolidate things...and I seriously need the help!

In my 1965 A100 Van, I'm going to an '85 318 V8 w/a 904 auto trans, from a /6 3-on-the-tree...I THINK.

If I could find the proper bell housing and related parts to keep my 3 speed manual trans, I might stick with the 3-on-the-tree, but it just seems that going to an automatic trans would make driving life much easier (particularly for towing a camper...see pic attached, if I attached it properly that is). Any thoughts on this: appreciated.

I need the frame brackets and engine brackets for the V8 motor mounts.

I need the trans mounting/support bracketry - whatever it is, as I expect it is markedly different from the manual 3 speed.

I've dropped the drive shaft for towing, but never even fiddled with the trans yoke/plate the drive shaft mounts to in the 3 speed manual trans - so if I need a different mounting yoke at the 904 trans tail to use my stock drive shaft, please advise.

I really appreciate all the help/advice I can get guys. Thank you! Steve

the 1st item to find is the frame and engine brackets, the extra set i had i sold to chrisnben, he did the engine swap recently, I have no idea if the 318 engine mounting hole locations are the same ??? maybe Rod can help on this, but there is allways a lot to consider, brackets & mounts, the rad , is the engine complete carb,starter,alt, duel exhaust I'D SUGEST asking a local tranny shop if the stock bellhousing will fit the newer motor, try to look in to items like this 1st the swap is not as cheap as people think,

Thanks. I already have the engine, just gonna have local machine shop do the heads and whatever else needs doing to make it fresh. I'm a bit more concerned with the trans mounting support (I can always fab whatever I need if there's nothing out there already), and the tail shaft needs to mate it properly to stock A100 drive shaft. I appreciate your response, and look forward to more - I never refuse help!

If your new tranny was used in the newer vans then the same crossmember should work with the existing frame. if this is all bolted togather rise the tranny till the engine is sitting level .
Line up the B-van crossmember tothe frame mark the holes , then you would need to drill out the frame front /back, and weld a stiffener sleve thru the frame and then use a thru bolt to hold it in place, on both sides. , i'm thinking if you use a newer tranny then you should ba able to use a newer drive shaft as well. and cut down to the correct leanth. hope Rod can add to this ...

From the front:
Radiator - ya gotta upgrade. The top hose is in a different spot and you are going to need a good radiator. Might as well get one with a trans cooler in it too, since yours doesn't.
Water pump and front cover (plus accessory brackets) - Going from the early to a late model V8 means the lower hose is on the opposite side. This is another reason to upgrade the radiator. The engine is a little bit longer too, but you should be able to get everything in and aligned if you are lucky. If the V8 had A/C, you are going to need pulleys and maybe brackets.
Thermostat - go with a 180. Our vans run warm anyway, and you don't need a late model 195 'stat.
Wiring - the /6 had the alt on the LF and the coil on the right front. V8 is RF alt, coil toward the back. Wiring will need to be adjusted.
Engine brackets - The 318 brackets might work, but that's up to you to check. Most cars and trucks had the brackets behind the engine ears. The A-100s have one in back, one in front. motor mounts should be any early twin stud style. Body mounts are V8 only, but I've heard that some guys use the right side /6 and modify the left side. I don't know more on that.
Throttle linkage/cable - you will have to change this. If yours has a cable, it might be able to be modified to work, or just need a longer cable to swing behind the engine and up. Linkage is going to be a booger. If you have good fab skills, go for it. Otherwise, I'd suggest swapping to a cable.
Fuel line - both fuel pumps are RF. Should be no problem.
Bellhousing - I would not trust your 3 speed behind a decent V8. You can get V8 3 speed bellhousings, they are fairly rare but not coveted.
Automatic trans - Only the A-100s had the exact short tailhousing. Motorhomes and early 70s 4x4 trucks with divorced transfer cases had a shorty too, but the MHs often had the E brake on the end and many do not have the pad and holes for the removable mount or the integral mount. You will have to find a good old school trans guy to walk you through what you need OR do as dix says and use a B van trans and crossmember. Don't forget the throttle pressure (kickdown) linkage and cooler lines!
Shifter - you can go aftermarket (easy) or try to find a donor for the dash shifter.
Driveshaft. Do you have a ball and trunnion on the front (top in picture)? If so, look into replacing it with a slip yoke (with that B van trans) or a driveshaft with a slip joint in it.


Exhaust - you can use the 85 manifolds if they don't dump too far back, or go with headers (do a search). Exhaust should be easy for a local shop or you can buy tubing kits thru Summit or Jegs.

Rear axle - they all came with 8.75 rear axles, it should be fine.

All of this is assuming there are not any current issues or previous hack jobs. Since this is a 40 year old van, this is a BIG assumption. Fix any issues you find along the way.

MUCH appreciated. Everything you mentioned I planned to do (though, I have been kicking around a "sick" idea of trying to fab a method to use my 3-on-the-tree column shifter for the auto trans), so it's good to hear that I'm in the right frame of mind. This '65 van is completely original - you can still see the red primer on the entire underneath! So I'm working from factory forward. In any event, I would LOVE to find a good dash-mount auto trans shifter assembly: anyone out there have one for sale?

The trans I am getting is a '73 A904 non-lock-up, freshly rebuilt but without a torque converter. If anyone has info on the proper torque converter for that trans, I would appreciate it.

Beyond that, my current concern is the drive shaft. It's easy to get one made, using a stock A904 front slip yoke (I'm guessing a 1350 unit), but since it is different from the stock trunnion style, I could use some input on whether going the "modern" route makes it better and easier, or worse. Any thoughts?

My van originally had a 3.91 rear gear, which - when I was in Fla on straight flat roads, I swapped to a 2.76, which worked GREAT for highway cruising (and put the speedo at under by minimum of 10 mph). Now in the Appalachian Mountains, I swapped to a 3.23 posi (with new housing outer oil seals, and new axle bearings). That was an effort to compromise between easier hill-climbing and some measure of highway capability without reaching 3,000 rpm. It's a process.

Thanks again for all of the help - it' a great thing!

Steve

Ditch the Ball & Trunnion, have a drive shaft made. Beside just jacking it up, have a bubble level on the intake (without carb) it needs to read zero, that will give the engine a 3* back drop. Make sure the engine trans is aligned right to left before drilling the holes and securing the trans hanger. Chrysler shifted the engine/trans assembly a few inches right of the center line. The rear differential is also right of center.

Thank you. Good points. Anyone know of a good driveshaft shop near Knoxville, TN?

They are not hard to do there should be some in your local phone book. you need to measure from the trany to the rear end so it can be made. the shaft will be under 3' so any drive shaft that works the tranny you are going to use would be fine. Just made sure it has no dents in it, they rebuilt mine while i waited,

Thanks - I have none (unless they modified the original trunnion one I have), so they'd be doin' it from scratch - but I agree with you: it should be easy (match the universal joint in the Diff., use a new slip yoke at trans and match that universal - put a tube in between).

If you have a drive shaft that fits the tranny. i'd use the slip yoke and the shaft, have them cut it down to the correct leanth. And weld the new end for the u -joint, That would be the least work . If you are thinking about swaping rear gears this would be the time to do it,

Indeed, but I have no driveshaft for it to use at all...I need one made from scratch. I would expect the 318 to be able to move the 3.23 posi rear gear well, and that gear should help on the highway I'd think too. No?

that's what i'm running, Sorry for some reason i was thinking you had a drive shaft, It doesn't hurt to look at a local yard, It's something that never had much of a resale market,

Turns out the 318 is a 1987 (out of a D150). Expect to go with a Pertronix Distributor and coil. Any suggestions for an aluminum manifold and reliable bolt n go 4 bbl carb? And which would you recommend: electric or manual choke?

Just my opinon  look for a older edelbrock with no egr, they sit lower , Giving you more room up top,
i'd run a electric choke, and if i could do it again i'd run a 500 cfm carb , I'm running a 600cfm now and I  feel  it's a bit much for a 318, when I called summitt racing regarding this they said 600 cfm,
But   racing my van  is not in  my future,