Did you change alt. wire to larger ga.?

installed a pertronix ignitor II, Flamethrower 0.6ohm coil

I eliminated voltage regulator, ballast resistor, and condenser.

It is a progressive linkage style weber,depending on what it's off it may be too small,perhaps not much better than the 1bbl,maybe check WOT with a vacuum gauge on the engine to see if its too restrictive,but if its the correct size,it should be an excellent carb.

with Pertronix Ignitors, don't you need to run a 3.0ohm coil to eliminate the ballast resistor? (0.6ohm you still need it correct?) and is your Alternator internally regulated?...just grasping at straws...

Lots of good suggestions to follow up on,to me it seems a little unusual to be able to run that much advance without pinging,perhaps the cam chain has jumped a tooth or is out? When you are satisfied all things are right internally it may be worth researching that carb a little more. It is a progressive linkage style weber,depending on what it's off it may be too small,perhaps not much better than the 1bbl,maybe check WOT with a vacuum gauge on the engine to see if its too restrictive,but if its the correct size,it should be an excellent carb.good luck with your search for better performance! Steve

The vacc. gauge is a good diagnostic tool and will definitely tell you what the engine is doing. (and a good tuning device when paired with the O2 sensor)

If I see things right the 38DGES is touted as a 400 cfm replacement/upgrade for Jeeps with the 258. I also see a couple of sources say it's synchronous instead of progressive (2 barrels open at the same rate). I did not see a quote on whether the 400 cfm was for 3" of mercury like the other brand 2 barrels either so compare similar fruit/ flow. I do know that if it is set for 400 cfm at 2"Hg. the filter element is too small (a Holley 350 on a regular early slant will like the full 14" diameter 2-3" tall pietin element at full throttle and load to get the most breathing out of the carb (lack of air flow will cause a rich condition if the jetting/rods/metering remains constant or put another way: less air and same fuel = rich condition....)

http://www.gregsengine.com/using-a-vacuum-gauge.html

Not the most complete, but is an easy to read chart form, best to get a long hose so you can watch the gauge as you drive, and plug it into a constant vacuum port that reads below the carb's throttle plates so you can see what the carb sees (i.e. throttle plate position changes/how much change...if you still have manifold vacuum instead of being close to 0 at WOT).

I'd take this and run with it before installing a wide band O2.

-D.Idiot

So which Hyd cam is the best bang for a street engine with a 38Weber

so you are using the Flame Thrower II (45,000 volt) coil?

there is some cam info for a slant six D-150 build in this thread..
http://www.slantsix.org/forum/viewtopic ... highlight=

the OE grind on the hydraulic cams really limit RPM's,, is your engine pulling much beyond 3K,, with the new parts, or is it still falling flat?
When I ran the OE engine set up through Dyno Sim,, the torque and HP had peaked and were sloping down by 3000 rpm,, the cam is limiting the ability to spin the motor fast enough to make use of the improved carb and exhaust..

guessing that you have checked the simple stuff like the throttle plates are opening all the way on full throttle..

also remember, a compression boost is the thing that slants need most,, that and better breathing,, which you have addressed on the external intake and exhaust sides,, but nothing in the head itself..with an ignition and carb makover, what do you think you will gain,, maybe 10, 15 HP,,

that is a great looking truck,, lots of experience and interest at .org