I'd have to guess that Proforms #66955 HEI distributor sports a gear I.D. that is the same as OEM HEI. Can anyone confirm .491" Shaft Dia.? I'll need to go bronze gear for billet cam and need to know size before I decide which maker of distributor to get.
Thanks

 

Why not contact Proform directly?
Their site has online support available during business hours or you can leave a message during off-hours.
http://www.proformparts.com/category...rs_Accessories

 

You betcha copper128, contacting the manufacturer, that's maybe step two after a thorough web-search, but I consider forums part of my web search and scan them also. Since I contacted Proform about the same time I posted my inquiry here yesterday (which was just before business hours Friday), I don't expect to hear back til early next week. So I initiated step three, ask my friends. If anyone of them wants to, they can respond with the answer. If not, I won't get a reply. Pretty simple

I believe MSD is .500. The rebuilt unit available from Accel is the OEM HEI, still has Olds P/Ns on the casting. Got my cheap eye on the Proform unit and as mentioned I run a bronze gear and was curious if the Proform shared the same size shaft as OEM. Same question for Taylor 640930 and Daves Unified 42720. Asking so if someone is willing to shout out an answer, it will remain available to others thru web searches.
I'd love to find any of these distributors offered with the option of not receiving any module or even coil at reduced cost, I have no need due to MSD CD and already have a new whizzbang coil.

 

If you need to as a last resort I can pull my preform hei out of my engine and check for you. Personally if you are going to modify give procomp a chance. I bough a procomp hei unit for my pops olds powerd Pontiac with one of my old engines . All I did was changed the curve and it worked like a charm for 55 bucks.

 

Wow, thanks for the offer! but no, don't go to that trouble. You aren't going to pull your dist. for this But I am positively impressed. Your a good man coppercutlass!! Thanks!! I'm too darn sure its .491 for that and if it isn't I'll be wrong and get over it.
Being a machinist has its advantages and bushing a .500 gear with bronze isn't a problem. I need to replace it about every 2500miles/125hrs/6months or so and it is getting kinda old, but the cam is a keeper for sure, car screams.
I was thinking about buying a unit from Summit, then decided to find out about the gear bore size, and by Monday I wouldn't be surprised if I decide to just rebuild a spare HEI from `78 Delta 350 I have. The deal is my mechanical advance has become gummed up and stuck 10° or so advanced again...again after a complete tear down, clean and lube within maybe 6 months and 2700 miles. I'm thinking my choice of lube and thermal cycles is gumming/drying? it up cause its isn't debris getting in there. I'm pretty sure I would've used a light grease but can't be positive, I have several kinds available here at home. I think I'll try using some sticky assembly lube this third time around, but I do drive it when its cold and don't want the plate to stick until its warm...heck, I don't know, I've looked for what others are using and didn't see anything special, except for peoples usual favorites like "White Lithium", "Lubri-Plate", "Silicone Dry-Lube", "WD-40", even "Dielectric Grease" was mentioned. The original is said to have a wax lube in it that melts at a correct temp, thus dispersing in use from the felt washer and not running down the shaft into the pan. Keeps it where it needs to be for proper advance movement and upper bushing lubrication.
The thing with the `78 HEI I have, I will likely need to limit it to 18-20° from it's likely 24° and I don't have a welder. I can get pretty clever but I just didn't want to fuss with it.
Anyways, I see I'm rambling on again...
Thanks again for your kind offer,
Patrick

 

There is a Comp Cams nitrided distributor gear that is available for use on steel roller camshafts. It's a .491 shaft hole and will last much longer on a street driven car than a bronze one.

Part# is Comp Cams 20442

I've run one now for 2 years with no signs of wear on inspection.

Give it a try

Greg

 

OK, Wow! Just did a comprehensive search of Comp #20442 and found a most interesting read amongst a group of GMC Motorhome enthusiasts concerning running a Comp Cams billet Hyd. Roller Cam and bronze dist. gear.
https://groups.google.com/forum/#!to...fi/oXexUHU2fQ4
It is an extensive E-Mail exchange speaking to bronze oil contamination and oil pumps, etc, etc. but at 12/2/11 and 12/5/11 you'll find some input from Comp Cams and I found it very interesting. Earlier on, it is mentioned how the Iron Gear was ...developed between Comp Cams and Jasper Engines.... What I got out of it is the iron gear #20442 was designed to run on billet material! I personally was told by Comp Tech about a year and a half ago that the only dist. gear able to run on billet was a bronze gear. I tried Crane and Comps bronze gears and although I ran only 1 Crane and a couple of the Comp gears I found them both equal in usable service life and quality performance.
Thanks for the tip gregvm, perfect timing!! I'll cancel my order to Summit for gear 442 and swap it for gear 20442 first thing by phone.
Patrick