'78 Doba 360 tweaks.

[morinRF]

My son's got the old doba on the road and is looking for simple ways to get a few extra horses out of the 360 4bbl. We don't have the time or resources to pull an engine or swap a cam shaft.

Is there anything like better plugs, carb tricks, or removing pollution control stuff that will give us an extra boost.

He last checked the mileage at 8 MPG around town. Any clues to help get better mileage would be helpful also.

Thanks

[fastmopars .inc]

340 cam, 340 intake 650 carter/edelbrock 600 holley.
302 heads from late 80's work best, your stock heads will work good enough.
put in the thin head gaskets from mopar.
install headers 2 1/4 inch pipe with good mufflers and at least 3.55 gears and have fun

[5th_Ave_Sleeper]

If it has a lean burn system, $hit can it and get an electronic ignition setup on there! You can get the whole setup from Ma Mopar for around $150. comes with new distributor, orange box, wireing harness, ballast resistor. Good instructions. everything one needs to completely convert from either a points or leanburn setup.
Probly wouldnt hurt to throw a new timing chain on it too
5th

[rumblefish360]

I had a '79 doba.
The above 2 posts is just about what I did to my Magnum.
K&N filter inside a stock '73-340 aircleaner. (Trap door housing, cool and stealth)
Carter 625 on top of a stock iron 4bbl.
The exhaust was off the stock manifolds, duals @ 2 1/4 with an
"H"pipe out to the bumper. I went to the orange box first, MSD last. MSD's wires and regular plugs.
The reward wa more pick up, but the mileage went from 10 or so on the hwy. to 20!
Never made the cam or headers. (Rats!)

[rustycowl]

I've got several of these things. You should be getting 15-16mpg min, lean burn or not. Of course, that is highly dependent on driving habits. If the lean burn is working fine, there is no need to junk it, however Chrysler electronic is much more straight forward and tuneable. If the engine runs smoothly, and starts easily hot and cold, look to some other things like dragging brakes, & fuel leaks.

[dwc43]

I'd use x or j 360 heads with the 2.02 1.60 valves. The best intake to use would be the Weiand acton plus dual plane with the 800 thermoquad. It will give you good milage and great throttle response when the back barrels come on. 1 5/8 headers are around 80 from summit amd 2 1/4 pipe and flowmasters or manifolds and 2 1/2 to flow masters both set ups with either an x or H pipe installed. Pull the accumulator spring out of the tranny and install the 5.0 ratio second gear arm and turn the line pressure up for some firmer and quicker shifts. Add a 3.23:1 gear or 3.55:1 at the exstreme end. Ditch the lean burn if it has it. If you have a tq make sure it is not leaking. Under the front jets are two small wells that are glued on at the factory and they have a tendancy to leak with age. This is the only real major draw back I see with this carb. Easy to epoxy them back on though.

[DEMON SIZZLER]

If you are on a 'buget', go with dual exhaust, vacuum advance distributor/orange box(or stock box from a donor car)and cut 1.5'
of the wiring harness for the ignition box from the donor car.

Stick with the T.Q. and seal with a dab of epoxy the two pencil lead holes down in the primaries below the inside of the front choke wall. Then remove the two 12 degree taper idle mix screws and install two 22 degree taper idle mix screws. Plug all unused vacuum ports with a vacuum cap. Adjust your metering tree piston height by the center screw. Lightly bottom the whole metering rod assembly and begin turning the center screw slot counter-clockwise until the assembly bottoms, then start turning clockwise noting when the assembly first starts back up and stop at 1-1/2 turns. Also remove the accelerator pump nozzle and drill the id's of the nozzles to .032".

If you need any further assistance, let me know, DAVID.

[gmblows]

If it is stock you may have a clogged cat.
Even if it was ok you would see nice gain with a dual exhaust.
cats
There are no magic spark plugs, basic tune up parts will do.
Try advancing the timing till it pings then retard a few degrees.