Brown D309 distributor cap applications

[John D.]

Re: Brown D309 distributor cap applications

hi mike,

I have the drawing for 1943047, it shows used with distributor 1110931, what other info on it will help you ?

john

[William C.]

Re: Brown D309 distributor cap applications

One small issue with the brown dist cap on a '65 FI car is that it doesn't fit under the ignition shield well, Factory spec was D-310 "short tower" as used on Oldsmobile and other GM applications

[Ken J.]

Re: Brown D309 distributor cap applications

Bill;
Can you tell me the height of the cap or nipples to tell the 309 or 310 caps apart. I want to check on my 65 Fueler and see which on is on it. Are they both brown?
Please advise.
Ken J.

[William C.]

Re: Brown D309 distributor cap applications

The D310 is black and the towers are about 3/8 inch lower then the D-308 or D-309. Also the D-310 has aluminum contacts, as do the D-308 used in all other Corvette applications (except L-88 & ZR-1) The D-310 was commonly used in Oldsmobile and other GM applications where right angle terminals and boots were used on the distributor ends of the sparkplug wires. The 1965 Chevy parts book specificaly references the D-310 (GM long number 1943047) for use with 63-65 FI applications as the only Chevrolet use for that cap. All others with the window cap used the GM 1942654 part number, service number D-308

[John D.]

Re: Brown D309 distributor cap applications

Although the original post was not asking about a D310 here is some more trivia to add that parallels Bill Cluppers post.
Part no. 1943047 for Cap and Latch Assembly was originally drawn up on 7-22-55. Catalog #D310. First use of Cap assembly was for 1110931 Distributor. Insert material-aluminum. Material of the cap or color is not mentioned!
Height of towers not mentions but every other dimension is. Must be another page for this part that I do not have.
Point of my post is to back up what Clupper said. The D310 was not created for a 63-65 Corvette. It was off the shelf from Oldsmobile application.
Now as far as putting a D308/ or D309 cap on a fuel car let me say in the old days I did just that. Probably 30 years before I knew squat I put a high tower cap on my 63 FI car and then had to smash the wiring down to get the shielding on. Talk about ignition missing. I remember the car sounding like it was running on 5 cylinders.
Just from memory I think that some of the older CC judging manuals for 63 listed the high tower cap as being the correct application. Now don't get excited as several of the later manuals list the low tower cap.

But what has this got to do with brown on a 65 Corvette? Only this. One time at Corvette Carlisle a vendor had a NOS TI distributor in the box for sale and guess what color cap it had on. Brown!!!
Now the NOS 070 points FI distributors that I own all have or had Black D310 low towers. Since they are over the counter service replacements you cannot reply on them to be correct for judging which is typical. JD

[Jack H.]

Re: Brown D309 distributor cap applications

You don't really need measurements to distinguish a D308/309 from a D310. Just put them side by side and the terminal height differntial is readily visible. That's how experienced judges distinguish. Here's a pix...

[Clem Z.]

Re: Brown D309 distributor cap applications

any time you install a new cap and wires slide the boots back on the dist end of the wire to make sure you get the wires all the way down into the cap. i don't recall how many ignition problems i fixed by putting the wires all the way down into the cap. if you run it long enough it will ruin the cap and the wires from the arcing inside the tower

[Wayne M.]

Re: Brown D309 distributor cap applications

....The D-310 was commonly used in Oldsmobile and other GM applications where right angle terminals and boots were used on the distributor ends of the sparkplug wires....

As Bill mentions; other applications also. I got this off a boneyard low-mile Olds 1964 HEARSE. Note the original wires ( dated 4-Q-63). The short towers really stand out.