I've purchased a 6A-L box and am seriously considering purchasing their spark timing control unit Part#8980. From what I can tell I need to use a locked distributor. What are my options regarding a distributor. Is it possible to lock my existing large cap GM hei and retain vacuum advance or will I have to buy another distributor. Anybody have any experience with this timing unit? Thanks guys.

I think i'v heard of using a spot of weld to lock it out. I dont see why this wont work but I have never gone through the troubles, anyone else ?
hope it helps

---Lance

Jack,

In lieu of welding the distributor, Accel or Holley makes a lock out kit that bolts in and is completely reversible for under $9. Your vacuum advance is removed to lock out with this kit, it is useless once you lock the timing anyway. The trouble with the 8980 is that it has a fixed timing curve but I believe the 8981 has an adjustable one. maybe I have the part numbers reversed, but you know what I mean.

I say, why make something that is completely adjustable mechanically and designed to go 100,000 street miles into something electronic that can quit at any time.

K.I.S.S. approach is something to think about.

Tom

I'm all for keepin' it simple and would prefer to keep the vaccuum can if I could have better than mixed results with distributors. I first had a mallory hei which I thought was going to be reliable piece. 3 months after I bought it the module went out. So I ditched the mallory and bought a GM distributor since everyone seems to have better luck with factory weights but regardless of the springs I used I can't get 20 degrees of advance out of it. I don't seem to either have the time, skill or patience(pick one) to make it work. No one that I know of has a distributor machine around here. When I called MSD about the possiblity of locking out a factory distributor they didn't seem to know much about that but were more than happy to recommend one of their distributors. :D I know you have done alot of testing with weights and stuff. Any tips there or suggestion on a aftmkt piece with mechanical advance that's does what it claims and works with the 6A-L.

Lance I thought about welding the plate to the shaft already and had considered possibility. I have a few to practice on.. smile.gif

Jack,

you can flip over the center piece that the weights contact to get more movement and you can also grind the contact points where the weights contact the center piece to allow more movement. Use original GM weights I have an assortment picked up from various places like swap meets and old distributors. The aftermarket kits are only really good for getting some springs

I hear you on the time and patience thing, I am in the same boat most of the time myself. Crane makes an electronic distributor now that you can dial in your curve electronically, real tempting for me as well, since now I have to slow my car down to qualify for my street legal class.

Hope this helps, gotta cut short right now.