Fitting headers in that truck could be a problem. The transmission crossmember is usually where most long tube headers would run. There was one company that made a run of long tube headers for Poly Sweptline trucks. I don't know if they are still available but Stan's might have them.

http://www.t137.com/dtapoly.bak/addpoly.php

There were 2 other companies that made long tube headers for 67-68 trucks with the LA and big block. One was Hedman and I don't remember the other one.

It's great that TTI makes Headers for the Poly 318 because TTI has quality stuff (you do pay for the quality). It would be nice if you can fit them to your truck and stick with the 318. But if not, I still say a stroked 400 would be the big block way to go.

I can speak from experience that Soopernaut is correct even though I have mods on my Poly that required further messing around with the installed engine height.

I adapted ford 302-351 Windsor headers to my Poly because there was no way I was going to pay $750 to TTI for a set of mild steel headers and then have to add another $300+ for ceramic coating. I bought a pair of new stainless steel headers for the 302-351 Ford with 3/8" flanges for $200 and then machined adapters out of 7075 aluminum to mate them to my Poly.

I also had to mess with the installed height of my Poly to make clearance for the intake I have and the one that is coming. My engine is at least 4" lower than stock. This resulted in the headers fitting perfectly with the frame. I also mated a TKO-600 5-speed to my Poly so the lower engine height worked out perfectly for the transmission and driveline as well.

- EM

Another vote for a stroker Poly here. Bruce Toth sells an adapter to bolt to the Poly ex. flange that lets you run a 331-92 header. I have your trucks twin but a 100 shortbed. Stroker poly goes in mine this spring.

Very nice truck. Really clean and straight. Yes it's the first series 1965 which has a 122" wheelbase instead of a 128. That 6" of wheelbase makes a difference in towing. The 128 is more stable.
The in-cab fuel tank has to go. There is a better place for a fuel tank, like in the rear where the spare tire might go. There are also spaces along the framerails that might be useful.

Even though the truck is a stock color, which was from time to time called Turf Green, duffers will try to convince you the truck is Forest Service Green. But what do they know?

Here are some sore spots on this cab style:
1. Fuel tank, already mentioned. If it leaks or cracks, you're swimming in gasoline.
2. Door latches. These are a major pain in the bum. They have an aluminum star wheel and it is not reproduced. These are like car latches from the fin cars. Vintage Power Wagons used to reproduce them, but not for 10 years or more. When my star wheel wore out I had to cobble a workable latch from a rear drivers side latch from around a '59 car.
3. The hood hinges wear out and the hood sticks up at the rear. Nice thing about the hood is that it opens up wide enough that you can pull the engine without removing the hood. If your hood hinges work OK, keep them lubed.
4. The truck bed is single wall. That means that any dent that gets put on the inside shows on the outside. I had a crankshaft roll and bang!
5. The tailgate is supported by chains which bang on the body in rough going.
6. Wheelwells are not in the usual places in the bed so a "regular" mat won't fit. That bed is an odd duck. 122" wheelbase strikes again!
7. I've had trouble with the taillights. Also no backup lights.
8. Fortunately the front turn signals are easy to find on Ebay.
9. The brake and clutch master cylinders are basically the same unit, with exception of the residual pressure valve on the brake master cylinder. It sure would be nice to have a dual braking system.
10. Good luck getting power steering.

Now on to the frame: Unless you are used to trucks of the '40s and '50s you will need to do a bunch of studying. This truck is set up with four point mounting for the engine/transmission. There are two mount points near the front like "normal". There are two mounting points on the bellhousing. The crossmember that the bellhousing mounts to is massive and sits right in the way of any non-custom header's collector.
The transmission hangs off the back of the bellhousing. Emergency brake is a drum on the transmission. The rear axle has no provisions for emergency brakes, at least not on the 1/2 ton.
The hydraulic clutch slave cylinder on the passenger's side of the bellhousing is directly in the way of any noncustom header tube.
The bellhousing wraps around the flywheel in such a way that you cannot remove it before removing the engine. It weighs about 72 lb. It should have bolt patterns for flathead 6, slant 6 and A engine.
You cannot pull the engine and transmission out of the front of the truck. You remove the transmission first, either through the cab or down to the ground, then the engine will come up and out the front.
The frame is set up for a front sump oil pan.

Now we get to the engine. The 318 Poly is NOT larger than an LA engine, physically. It just looks that way. It has the same deck height and bore spacing. Crankshafts are the same. That means that 340 stroker cranks just drop in. Rods are the same. Oil pump is the same. Distributor is the same. What is NOT the same is pistons, camshaft, cylinder heads and valvegear, intake manifold, exhaust manifolds. IF you like to feed the weirdness you can build a big Poly motor. But it will cost you big bucks. There are about five intake manifolds that are not 2-barrel. None of the intake manifolds is currently available for less than $500.There is the Edelbrock P-600 3-2s, usually Stromberg base, the 2-4 barrel Fury manifolds, currently less expensive but take two carbs, the single 4-barrel stock intake, running around $600 last time I checked, the 7503 Weiand, not available new and usually getting around $500, and then the new one that currently retails for $670 or so, if they are actually making them. Camshafts are limited to regrinds except that Camcraft has a bunch of new cores, $185 apiece, but then you have to get the core ground, so I think we're looking at $300+ for a brand new cam. Regrinds of stock cams are not too bad at under $150.
Because the valves are in different places on a poly than on a Wedge, pistons are at least semi-custom. Sealed Power makes stock pistons in their antique line but I think they're about $400 a set.

Don't get me wrong, I like the Poly because it's weird. My engine was a stocker with Weiand 7503 and Holley 570 Street Avenger. I used a Direct Connection electronic distributor kit and finished off with dual exhaust. My truck got an honest 16mpg with a lot of rejetting of the carb because I live at altitude. The Poly heads are actually better than the 318 heads and the Poly in near stock trim has more power than a LA 318.

I swapped to a 1986 roller cam 318 and used the 360 hydraulic roller cam and a 1975 or so stock 360 four barrel intake with the 570 street avenger. I used the late model exhaust manifolds with the old exhaust system and picked up 6 mpg right off the bat. Put that in your Poly and smoke it!

If I was doing a ground-up reconstruction I'd look seriously at a GIII Hemi, take #200 off the front end and make steering easier.
A B/RB will bolt in and a B makes more sense for room especially as you can build them to 500 inches or more.
I didn't think the engine bay looked empty when I substituted the LA for the A.
One last thing,,,,,The NP420 transmission has only synchronizers in 3rd and 4th gears.

R.

Feel free to PM me with questions.

R.

The A series block is mostly the same as an LA except in wall section of the casting so it is heavier and can usually take a larger re-bore than an LA. With heads attached however, the Poly IS physically wider than an LA.

- EM

The star wheels are being reproduced. The same guy can get you stainless steel lined brake and clutch master cylinders.


CPP makes a power steering kit for this truck.

The 65 and later trucks had a provision for emergency brakes on the rear axle. It was no longer on the rear of the transmission on light trucks.

Thanks for all the info Dogdays, I was already aware of most of it though.
Yes, the color is Turf Green.
This truck actually has three gas tanks with a selector valve on the driver's side floor. It has an extra tank in front of each rear wheel, that you would fill from the inside of the wheel well. see pic. (I'm just glad it had this style, instead of the others you see that have holes in the side of the bed to fill the aux. tanks.

The original owner towed a fifth wheel around the country with this 122" wheelbase truck. Scarey!

The Driver's side door latch "star wheel" is junk and needs replaced. I guess I'll be looking for one of these.

My hood hinges are in good shape and the hood closes/lines up real good, so I will lube up the hinges to keep it that way.

Headlights are the only lights on the truck that work.

I replaced the clutch master and rebuilt the brake master. I still have no brakes, I think it's rust in the lines, but at least I can start it and pull it in and out of the shop. Emergency brake stops it for now. Seems like the brake pedal swing arm needs lubed up, the pedal doesn't want to come back up when pressed.

My emergency bake is on the rear axle brakes, not on the back of the trans.

I've been doing some research on the Poly engine, and havn't made a decision on what I'm going to do long term for drive train. I needed to replace the passenger side exh manifold gasket, and I am attempting to remove three broken studs right now. Are just the top bolts in the water jacket, or are all of them? Want to make sure I put sealer on the correct ones.

Soopernaut, who is this guy? "The star wheels are being reproduced. The same guy can get you stainless steel lined brake and clutch master cylinders."

I saw some info about the CPP power steering, but I'll decide on that after I get it driving on the road. Manual steering never bothered me in my 70 Cuda.

Thanks again for the info guys.

Really sweet looking truck.

[quote=Red383]
For the engine, I’m looking for opinions on which direction I should go. I kind of like the look of the wide 318 that is in there, but is rebuilding it a good option? Parts availability? Are headers and intake manifolds available?[quote]

I like the idea of the old poly.
A rebuild is no more difficult than any later V-8.
I believe the shortblock is the same.
Might be want to see if a stroker kit would work.

There is some progress being made with Hot Rodding the Poly.
https://search.yahoo.com/search?p=polysuperpac.com
Don't know about headers but the motors are getting some LOVE.
I've read a few articles in "Chrysler Power" magazine,

[quote=Red383]
Emergency brake stops it for now. Seems like the brake pedal swing arm needs lubed up, the pedal doesn't want to come back up when pressed.[quote]


I just went through this with my 77 van. It was the rubber hoses had gone soft insde and would act like a flapping rubber valve to keep the fluid from returning unless I manually pulled the pedal back up.

Not a bad idea to replace all the brake components including the lines.
Not too hard a job and well worth the effort.


The split rims gotta go.
They are considered to be dangerous.
I doubt you could find someone to mount anything on 'em.
I am no help in finding replacements.
I used 18"X 8" aftermarket wheels.
Great tire availability.

Your not going to find "new" tires in the 16.5 size.

He is John Geidl aka PowerwagonJohn. He doesn't visit computer forums much, is not a member here and prefers to do business by phone or email. He has been in the Dodge truck hobby for a very long time.

" Camshafts are limited to regrinds except that Camcraft has a bunch of new cores, $185 apiece, but then you have to get the core ground, so I think we're looking at $300+ for a brand new cam. Regrinds of stock cams are not too bad at under $150. "

I just paid $70 for a regrind of my OEM camshaft but to a spec I wanted. This was at Oregon Cams and they have several patterns available.

- EM

Don't be surprised if that manifold gasket turns out to be a cracked manifold. If you find a poly in a boneyard it will almost always have a driver side exhaust manifold but the pass side is almost always gone.

Bruce Toth makes adapter plates that allows you to bolt GEN3 hemi exhaust manifolds or headers to a poly. Anything would be better than the tiny log manifolds they came with.

.100" overbore and a 4.25" crank gives you almost 430 cubes.

Kevin

Congrats on the truck. Looks like a decent start to a cool truck.