Which MSD distributer-427 FE with 2 4 barrels
 

I have a 427 FE with a twin 4 barrel Edelbrock step. I have a 6-AL box already installed and The car has a modified duraspark distributer currently and the mechanical advance is exceeding 50 degrees total timing. I don't feel like totally stripping down this distributor to correct the advance issue. Summit Racing shows that I should use #8594. Problem is that it is 5 1/8" in diameter which, when I measure my space, I am not sure if it will clear between the overflow tank and front of my carb. Anyone have any experience with this?

Your not going to go out a buy a new distributor that all you need to do is stick it in and bolt it down. You still need to set it up for your engine. Odds are that you would be better off looking at your distributor. There may be nothing wrong with it. It may have always been set up incorrectly. Or it may just have a broken spring on the mechanical advance.

This is a big subject and you haven't said if your current distributor has vacuum advance.

What is your base timing and what it the timing at say 2000, 3000, and 4000 rpm, with vacuum disconnected if it has it?

My guess is there is no vacuum advance. Base timing is 22* and mechanical is adding 30* giving 52* total timing (give or take), but I could be wrong.

Lots of people set them up like this, but usually limit the mechanical to 20*. So your car may be doing exactly what it was set up to do and nothing has changed.

In my opinion 50* is way too much timing. I think 40* total is the upper limit. Usually an FE needs between 36* and 38* total timing at WOT. Again in my opinion any street driven car should have vacuum advance. Plenty around here will disagree and argue it is not needed. Well you don't have to have any advance, lawn mower engines run just fine with fixed timing. All I can say is Henry Ford new better, when he design the Model T. Just because you can get buy without it is no reason to do it.

First let's understand exactly what you have.

Yes it has Vacuum advance but it is disconnected when I obtained the numbers. Here they are.

Base advance: 16
1500 rpm 20
2000 rpm 24
2500rpm 30
3000 rpm 36
3500 rpm 40
4000 rpm 45
4500 rpm 51
I stopped at this point.......

Correct me if I am wrong but it appears that is is not a spring issue but one where the advance stops are way too lax for the engine. The only solution I have found is to find a distributor with the correct stops. (like a 10) or weld a bead on the existing stop. I search all over the net and I didn't find an easy solution for this.

The car already has an MSD 6-AL ignition box in place. It seems to me that the easiest route to go is get the MSD 8594 pro billet distributor. I understand that I might need to change a spring or a bushing, but it doesn't involve welding. My only concern with the 8594 is if I have clearance. I have a twin 4 barrel setup and an overflow tank in the front and there isn't much room in between. Thoughts?

Looks like your advance curve is ok to 3000, so the stops have either broken off, or some other malady.
You say modified, as to how modified, we will find out we it gets pulled apart.
Why spend $500 on a new distributor, when yours will be sorted on a distributor machine with a correct curve for the engine for about $100?
Gary

Contact these guys for a custom curved distributor. Parkland Performance Auto Machine - Home. Look under Services on their site. They can re-curve your stock distributor to your specs.

Thanks. Il give them a call.

Call Gene at D.U.I. in Memphis Tenn.

Phone: (901) 396-5782
Fax: (901) 396-5783
info@performancedistributors.com
2699 Barris Drive
Memphis, Tennessee 38132

check out Summit, Jegs or Speedway they all sell D.U.I. distributors

I bought one for my 427 thru Summit cost $280