Guys,
I searched long and hard and could not really come up with the specific answers I'm looking for... Have an awesome '75 D200 Club Cab 8' bed with only 50K miles from AR, and simply put, I'm building the engine to tow, and need to be able to pull my 18' boat out of the water (total boat and trailer ~ 4K lbs).

Guessing starting with basically following the recipe from the Mopar Performance April '03 issue Six = Eight is a good idea right? It runs fine and super smooth on the 1bbl and compression checks out great on all 6, so the bottom end is staying as is (sticking with stock bore and pistons) It's understood that I really don't want compression too high if I want low end torque so is decking the head ~ .050 for ~ 9.0:1 still a good idea (do need some RPM power for towing...)? I really have 4 basic questions (but welcome advice):

1. Cam selection for low end torque, just not finding the awsers... Please make a couple suggestions. Again, it is a '75 so solid lifters, do not see the need to switch to hyd.
2. 2bbl vs 4bbl, my question is primarrily thinking about sitting on a 12% incline boat ramp (0 speed, and pulling the boat), could the 4bbl cause issues / stumble / dump too much fuel??? Should I stick with a 2bbl, if so what size? (again following the basic recipe from the Mopar perf April '03 minus the bottom end stuff and likely a different cam). Certainly I understand if I limit the intake, high end hp will be affected... Have a stock 2bbl from a '77 360ci, would that be a decent match?
3. Exhaust / Headers, is there a set up that claims / delivers better low end torque? Plan on running a single 2.5" to the back, this is not a race car don't need loud or dual exhaust Can not imagine ever spinning her much over 4500 RPM, but certainly not over 5000 RPM, no need, right?
4. Is the porting and combustion chamber work not as important since I plan to keep RPM's lower?

Already have 4.11 gears, stock 3 spd auto is staying. Feel free to share your thoughts!

Thanks guys! I'm really excited about this project and have spent hours pulling info, and appreciate your suggestions! When I figure out how to load a photo I will, she is a beauty!

_________________
Ben
75 Power Wagon 225ci
75 D200 Club Long Bed 225ci
77 D150 360ci
72 Scamp 340ci 6bbl
Too many half done projects to list;-)

You can stay solid with no problem. For low end torque (this means under 2500 rpm/typical street speeds). You will be shooting for a RV style cam with short duration, but more duration and lift than stock. This will fall to the Erson RV-10, maybe RV15 depending on your compression and engine prep work, the Comp Cam 252, or the MP '243' cam.
Since you are staying just a little above the "stock" build the 2 barrel would be a fine fit especially if you are only doing a clean up of the ports and retaining the stock valves in the head. The 360 Holley 2245 will be hard to adapt without some custom adaptor plate work, also your engine will not be that hipo so the carb will be rich out of the box and not be a good match in calibration either...The Holley 2300 would be easier to get parts for if you went that direction (no bigger than a 350 cfm)
Stock manifolds with the larger pipe should work fine for now, the RV setup will be only good up through 4000rpm at this rate. If you were going for lots of 'breathing' like a 4 barrel and bigger valves and porting and 5000 rpm all the time then dual exhaust and headers would be the ticket...
Light porting and cleaning out the casting flash/irregularities is more important here than opening up the ports for more flow.

You will have to take your engine apart to see how far down the pistons are in the bores before you can figure out how much to take off the head to make 9-9.2:1 static compression...given what I know about the 1975-1976 forged crank engines you will most likely need to cut .1-.11 to make it up to that point assuming you use a felpro gasket.

You also will need to check your bores, if you increase the top end your rings may not like the extra stress and something will give at the worst time.

-D.Idiot

I have owned a 77 pick up and a 76 Volare both with Super Six setups. Both towed my 19" Reinell Deep V hull with an inboard 6 cylinder Volvo just fine. So now worries on the boat launching ramp.

DI suggestions are right on!

I like running the higher compression for the extra low end torque.
I run 2.5" exhaust with two FlowMasters in series which are super quiet.
I would regrind your cam to the RV profile. Mine is the .435 lift 254 style. That way when you deck the block the stock push rods still work fine. (They grind a fair amount off the back side of the cam which makes up for the difference that you take off the block and head).
You could run the one barrel but you would be in the power valve more getting up to speed. The two barrel does breath better and is more efficient.
As you can see in the "Engine Matrix" my build up I did a street port and bowl blend behind the valves.
One more consideration would be to recurve the distributor to make the rebuild come to life. Generally stock distributors provide a lazy feel to a SL6, even a new rebuild. The recurve made mine feel very peppy!

Check out the Engine FAQ section: Engine Matrix for various build ups. Doc really coached me through my rebuild. His build and mine are very similar. I wanted the extra torque because I put a 8 3/4 2.76 ratio Sure Grip in my Dart. It rarely turns higher than 2800 rpm tops. It will scoot right up to 4000 rpm though. Cruise on the freeway is 2200 to 2500 rpm.

I really like the SL6. When rebuilt for torque it will feel like a 318. Click on the red link below for pictures.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG