Need ignition upgrade help/advice.

[5Tractorguy]

Originally Posted by AZKen

Wow! , this post has been hijacked from the original poster.

Right you are... part of the reason I try to stay off forums sometimes unless necessary.

You guys mind as well just have at it and keep rolling, as I said before I'll update as I go.

I have to get a sticker this month and drive it in the Memorial Day parade. So by next week I'll have a chance to play with the engine for a bit. I'm going to check the vales again too. I did them once but the engine wasn't hot enough so I'm sure the clearances are off.

[5Tractorguy]

Checking in for an update...

Over the past month I reset the valves while hot (some were pretty tight). That made a bit of a difference now that they are opening and closing properly.

I also ordered a set of .059 jets, two sizes up from the recommended. Just got through installing them and going for a test drive. Definitely a bit more responsive when shifting up. Top speed pulling a hill at 45, seems better.

I may take it to a cruse night tomorrow and see how it does on a short trip power wise. I should really throw a 2000lbs tractor on the back and see what happens...

The initial goal is to do a 85 mile round trip to a tractor show weekend of the 22nd and 23rd. Lots of hill climbs on that trip, could have a nice parade behind me!

[bigblockv6]

Get rid of the points ignition and go with electronic ignition. My choice is the GM HEI and there is the Pertronix which is an easy retrofit because it fits into your stock distributor.

[bigblockv6]

For the HEI upgrade check out jolly's www.6066gmcguy.com site under V6 performance upgrades. For the Pertronix conversion go to www.vintageperformance.com/retrorockets.

[5Tractorguy]

Originally Posted by bigblockv6

Get rid of the points ignition and go with electronic ignition. My choice is the GM HEI and there is the Pertronix which is an easy retrofit because it fits into your stock distributor.

Thanks Bigblock. That looks like the next upgrade I'll be doing. May lean towards building the HEI distributor if time allows. A couple owners before me converted the 350 on my '77 GMC pickup to HEI. For an older carbureted engine, it starts fast and runs great.

[bigblockv6]

That's odd because a 77 GMC would have come with an HEI as standard equipment

[5Tractorguy]

Originally Posted by bigblockv6

That's odd because a 77 GMC would have come with an HEI as standard equipment

Maybe it was. I don't know much about the 70's years... The guy put a mild cam in it along with a Edelbrock 500cfm 4 barrel. Distributor was replaced too with one of those fancy aluminum looking ones... blue distributor HEI cap... so I just figured it was converted.

He used to pull a trailer with it from Colorado to New Hampshire so it was built up some.

[massey478]

5tractorguy, I put on an MSD6 and MSD coil on my 478 in the Massey tractor. The points in the distributor only act as a trigger so they do not wear like they do when running normally. It made a great difference, starts better, runs better, plugs stay cleaner with my larger jets. An MSD6al has rev limiter chip capability if you want that. There are many MSD units for sale on Ebay. I have bought five of them there to put on various pieces of equipment, cars and trucks I have. I have never run a Pertronix so I cannot offer a first hand experience to compare them to MSD. I just know we are very happy with the MSD system.

[Quigley]

Originally Posted by massey478

5tractorguy, I put on an MSD6 and MSD coil on my 478 in the Massey tractor. The points in the distributor only act as a trigger so they do not wear like they do when running normally. It made a great difference, starts better, runs better, plugs stay cleaner with my larger jets. An MSD6al has rev limiter chip capability if you want that. There are many MSD units for sale on Ebay. I have bought five of them there to put on various pieces of equipment, cars and trucks I have. I have never run a Pertronix so I cannot offer a first hand experience to compare them to MSD. I just know we are very happy with the MSD system.

+1 Dave. I would add to use premium wires.

[POWERSTROKE]

Originally Posted by bigblockv6

That's odd because a 77 GMC would have come with an HEI as standard equipment

Yes, HEI was used as early as '72/'73 model year on some engines, Chevy used it a lot in '74, and on everything in '75.

I had a '70 Nova with 307 V-8, and a '77 Firebird with 301 V-8, HEI was a much better system.

Installing an MSD 6AL sounds like a great idea. They make speed limiter chips low enough to match the Big V-6's operating range, 3000-3800, and 4000-4800. Take your pick.