[Adrenaline_Fiend]

Ok, I've figured out where my headache is coming from with my carbs on my tunnel ram setup. They are 4160's, 600cfm. Here is what some jack*ss previous owner did too them: filled the vacuum port for the diphragm's w/ lead or something, removed the vacuum diaphragm's, put a bolt on the secondary linkage so that the rod would mechanically open them, removed the metering plate on the secondary side and added a metering block ( it's the kind with no power valve hole) and it has jets, and there is no accelerator pump for the secondary bowl. I was reading my holley carb book and it looks as if somone tried adding the kit that makes them more like 4150's. I can't put the vacuum secondaries back on due too linkage problems and the vacuum hole being filled, but should I put the metering plate back on and remove the metering block? My engine is still running fine at part throttle, and it pulls hard at 3000rpm's as long as I ease into the pedal, but my plugs are still dark and if I floor it or stall it, it tries too die and backfire through the carb. Oh yeah, last weekend I added an MSD pro billet w/ vacuum advance and a 6AL box too help burn all the fuel. Well, what do you guys think? I was also wondering if I should start playing w/ the distributor to bring the advance in quicker, or if I should keep fiddiling with these carbs.


And of course here's the setup for the record again:
350 out of a 72 pickup
stock heads
270H magnum cam
MSD probillet distributor w/ vacuum advance part # 8161 (i think)
MSD 6AL
Accell 8mm wires, no cracks, brand new
NGK v cut plugs, .055 gap
MSD blaster 2 coil
Edelbrock Pro Ram 2 manifold
Hooker comp headers
2400-2800 TCI breakaway stall
3.08 one legger
...and of course the FUBARED carbs as per mentioned above.

primary jets: 63's
secondary jets: 65's

when I added the MSD equipment the plugs all white, that's why I jetted it back up. I've tried locking out the secondaries, and adjusting them so they come in quicker w/ no better results.

My timing is set at 10 degrees initial, and the car starts up just fine. I currently have the heaviest advance springs in (slow advance) and total timing is 32.

The whole deal with the secondary metering block just dosn't make any since to me because these are not double pumpers, could someone please explain how the secondary system could be functioning with them?

Well that's all the info I can think of, thanx again.

[johnsongrass1]

Seems someone has started a project without finishing it or slapped a carb together so it could be sold as is. Without the secondary pumps the carb will go really lean and pop thru the carb. It will also give you tuning problems. I would just collect the part's you need to either finish converting to DP or set it up with vacuum secondary's and drillout the lead plug. I would recommend going with the vacuum secondary with the info you have given. Keep at it. You have already figures out the hardest part, knowing what's wrong with it.