SBC Distributor

[James Ratliff]

I have a 71 nova with a 355 in it. It has a stock HEI distributor in it. I just changed the cap and noticed the rotor has cut a slot in the cap. It has also broken some of the internal ribs in the cap. It is really close to the firewall.

1. Could the motor be flexing and moving enought to move the cap on the distributor??
2. Is there a smaller cap I can put on it??
3. Thought of going to an MSD billket unit as I already have a 6al box on the car. Is that a smaller cap?? Looks to be.
4. Anyone use the summit billet distributor (MSD knockoff)? Will it plug into my 6al box??

Thanks
James

[Oldsmoduck]

Make sure the cap is mounted correctly to the base.

[HonkIfPartsFallOff]

engine shouldn't move enough to break a dist cap. and even if it was moving it would move side to side not for and aft. Nova's eventually came with HEI's from the factory and i'm pretty sure they didn't do anything to the firewall to make it fit. I'd just do what Olds said and make sure it's installed all the way seated and all 4 hold downs are firmly in place. unless of course you want to pop for the MSD dist, then you can get a smaller diameter dist. good luck.

[adamsvega]

ck the shaft play and be sure it did not wear out the bushing and wobble or walk up into it!

[Gameracing]

Nova's (any year) are extremly tight with an hei, to the point it's hard to turn the distributer to set timing. I personally use Mallory unilite's, much smaller and work great, three wire hookup. I've had one in my chevelle for 15 years.

[James Ratliff]

I checked the endplay. I had to shim it last winter when I checked it. I am wondering if that is not what it is again, but I didn't have that problem before. This was not an issue until I recently did a head swap and went from fuelies to dart iron eagle 200's. Could the car be making that much more power with just that head swap?? It does leave more violent on the street but I haven't had it to the track to see a time difference.

Could the pinion angle be so far off that under load it is moving the engine in the up down front to back direction enough to push the cap forward a little?? Just another thought.

As for the mallory unilite, will my 6al box plug into it??

Thanks

James

[Gameracing]

All you need with the unilite is a hot, ground and trigger, the trigger will plug into the 6al

[jeffmotorman]

The HEI distributor was not used in the Nova until 1975, at which time the firewall was reshaped for distributor clearance. Yes, the engine can move on the motor mounts enough to cause rotor/cap contact when the cap touches the firewall. Also check for a broken trans mount. The Nova subframe can move as much as 1" forward and backward when the original body/subframe mounts deteriorate. Careful if you decide to move the firewall with a hammer as it can interfere with the wiper linkage.
The MSD 85551 distributor is the same size as an original 1971 points distributor cap and the unit plugs directly into your 6AL box. This is a good ignition system when used with a good coil.

[James Ratliff]

I have a blaster 2 coil on it already as well. I also have a 2 step and window switch I want to use to spray with and it is all MSD, that is why I would like to go with an MSD unit.

The 85551 is a mechanical advance only isn't it?? Would you want that or the 8361 with vacuum advance on it for the street??


Thanks