As of right now I have a mallory HEI distributor but after talking to a guy at Mallory today I dont think I will for long. The guy pretty much told me that their HEI distributors are junk for any type of performance applications. I do have it used with a MSD 6al but he still said there are many limitations to the piece. This might explain why my cousins motor which is a built 350 with AFR 210 race heads and a large solid roller cam stopped making power around 5500 rpms???? What do you guys think about the HEI distributors from experience and what are the limitations? What do you suggest that is a budget freindly replacement but not a limiter in performance that I can buy if I need to.

Another issue is I have been having trouble with the motor idleing and coming down off of a rev fast. Throttle response isnt that great either. Talking to the guy today it might make some sense because the dizzy doesnt allow you to change the mechanical advance in which it is set at 22. I dialed the motor in to have 36 all in. Which leaves me with 14 degrees initial which my motor needs more due to my cam size probably in the range of 18 or so. The motor runs better if I hook up the vacuum advance to the full manifold vacuum source which kinda shows that I am not having enough timing because it runs better with more but still not right.

When it revs it doesn't come right back down quick so I thought maybe the advance inside the dizzy wasnt working properly and when I opened it and shifted the rotor and let it go back with the pressure of the stock springs in it(relatively strong springs), it wouldnt always close all the way it seemed, which could be a reason for the motor not coming down off a rev right if it is putting more advance in it. Sorry for the long post but I just need to get some advice on what to do so I can finally get this car on the road. Thanks for the helps guys!

i'm using a stock GM hei shifting at 7k with no drops in power. if your getting 36 deg total timing your idle timing doesn't really matter as long as its not too advanced to start the engine. it wouldn't hurt to try another dizzy. i did have a problem similar to yours but is was a fuel pressure problem.

Large cap HEI distributors even with an OEM module can easily go to 7000 rpm.

If this is a race only situation, lock out the distributor so that's there's no mechanical or vaccum advance. Set your timing to whatever total you want (36* etc) and run it. If the engine is hard to start with that much advance, invest in a start retard or MSD has an adjustable timing control so you can manually change the timing up to 15* from inside the car.

Thanks for the replies. I have never locked out a dizzy and dont really know how to. Is it just replacing the springs with somethign that will keep them in that closed position? If my timing is set at 36 all in will that be the timing I get when I lock it out or will have have to initially advance or retard the timign to get it to start correctly? Any pictures or advice on how to lock out the distributor is appreaicted because if the motor still has problems running I will be confused because everythign else seems to check out. Also on the fuel pressure situation I will check again when I run the motor but I'm pretty sure FP stays right at 6 PSI the entire time. Thanks gain guys!

If your going to switch buy this. I ran one for years on the street with no problems. Now i have a crank trigger and would never go back to another style. http://www.jegs.com/i/MSD+Ignition/121/85551/10002/-1
To lock out timing you will need a advanced timing light, you may not need one but its the easiest way to do it. Set the dial on the gun to 36 and line up the marks with 0.

to lock out an HEI dizzy you have to remove the weights and the springs and weld the metal pieces together that the weights used to sit on. I have mine locked out and it is great. doesnb't start hard when warm or cold. timing is set at 34 degrees

wouldn't be easier to use a tbi distributor with an hei module? then you wouldn't have the extra heat from the coil and it's more compact in size.

I have heard people talk about wire ties being used to lockout the dizzy. I know this isnt a proper method but for me I really just want to see if it will cure my problems and then I will do it the right way such as welding or something of that nature. So if I remove the springs and just put wire ties across the two places where the springs were that will lock it out correct? If my time is set at around 36 all in and probably in the range of 14 degrees intial what will it be set at if I lock it out? Will it be only the intial timing and I need to put more advance in it? Just wondering so I know what I might need to do if the car doesnt want to start over if I should advance or retard it. Thanks again for the help guys!

the ties will keep it retarded. need to advance after that

Alright I made a metal plate to go over the pins where the springs clip on to keep it locked in place. This should be very close if not the same position as the springs when there on there. I know it was said it would retard it but what should it be at exactly? Is it just going to be the initial timing so about 14 degrees when I go to crank it or is there some from the distributor just being in that starting position? Should I try and advance it a little before starting it up ? Thanks again guys!

edit: I know kens86 said you have to take the weights off too but is that just if your going to weld it ? If I made the metal plate to go over the pins where the springs used to be is that locking it in the right position or do I need ot remove the weights too? Thanks again