New Ignition

[rgtrough]

Hey guys, I am wanting to change out the original ignition to a HEI system keeping the factory tach. Please offer up some feedback on quality systems keeping in mind I am going to continue to build this engine into the 400+ hp range. Also I need some high quality ceramic coated headers. Thanks for being here for guys like me. :cool

 

[jim coulter]

I have a 71 with mechanical tach, I went with the MSD pro billet distributor for corvettes. It has the provision for a mechanical tach. I also went with the MSD 6AL ignition box, but not sure how well I'll like it since I only ran the car for a short time, and now its back on stands while I replace the rubber in the front end, and the brake lines.

 

[Jack]

GM HEI & 75-77 vette tach

Hey guys, I am wanting to change out the original ignition to a HEI system keeping the factory tach. Please offer up some feedback on quality systems keeping in mind I am going to continue to build this engine into the 400+ hp range. Also I need some high quality ceramic coated headers. Thanks for being here for guys like me. :cool

rgtrough:
First, welcome aboard CACC! I think you have a 74? If you want to run an HEI & keep Original factory MECHANICAL tach then your choices are very limited ... there's a custom tach drive HEI dist priced about $500-$600. The MSD setup is great but it is not HEI and also runs about $500-$600.

But here's what you can do if you want to run an HEI. Acquire a good used, rebuilt or repro ELECTRONIC tach from a 75 thru 77 vette (78 up won't fit). It'll fit-swap right into where mech tach is-was and will connect with HEI (all 75-77 sharks came with HEI). I bought a good used 75 tach for about $55. Many folk report they're pleased with Dynomax ceramic vette headers ... about $215 at jegs.
JACK:gap

 

[rgtrough]

Hey guys, thanks for the replies. I really like the '75 tach suggestion. If you have the time could you explain the benefits of the MSD pro billet distribritor and the need for the electronic box. Thanks again.:cool

 

[Hijinx]

You have two choices, and I've done both. You can get the Pentronix Ignitor II to replace the points and go electronic using your existing distributer. Or, you can go with the MSD billet unit and 6AL. Pentronix is around $100, the MSD setup will set you back roughly $550-650, depending on where you get it. The Pentronix setup works well, and increases performance of the ignition systems. The MSD is a full performance setup.

 

[jim coulter]

...could you explain the benefits of the Msd pro billet distributor and the need for the electronic box

I went with the msd distributor because I wasnt sure where I'd mount an electric one, on the column, on the dash, or replace the one in the dash( but then it wouldn't match the speedo) So the distributor let me maintain my original tach, which I really liked, no bounce smooth operation and it matched the car since it was original. I cant remember if I had to have the box, but since I wanted a rev limiter (since I have a 4-speed and might miss a shift at wot) the 6AL made sense. As far as why MSD, I didn't know what kind to get, so I hung out at the track and asked around and alot of people were running the MSD and liked it. I figured if the guys that are at the track every week pushing their motors and their cars to the max liked it, it must be pretty good. So I went with MSD.

 

[Jack]

Hey guys, thanks for the replies. I really like the '75 tach suggestion. If you have the time could you explain the benefits of the MSD pro billet distribritor and the need for the electronic box. Thanks again.:cool

First off, MSD boxes & distributors are great & quite powerful ... but IMHO are overkill for most street cars. Don't get me wrong ... I like em, I have two MSD boxes. MSD distributors and boxes, like anything else, do fail occasionally; when they do you'll probably be walking 'cause replacements/parts not found just anywhere. I know for a fact MSD dist triggers, like anything else including an HEI's trigger and module (amplifier), will fail occasionally.

Pertronix is a good choice ... in essence; it's a trigger & amp that fits into points-type distributor. But keep in mind, like the MSD & other mods ... replacements/parts not available just anywhere.

All chevy V8 MSD pro billet distributors (except ready to run pn 8360 and HEI pn 8365) REQUIRE an MSD box or similar box such as Crane Hi-6, Mallory Hyfire6. The MSD tach drive vette dist pn 8572 REQUIRES box also. They require box because dist designed having only two functions ... to trigger an amplifier (msd box) and to distribute the output from coil to plugs.

Rev limiters are a good thing ... they come on board some boxes; others not. A stand-alone rev limiter can be added to points, HEI, MSD ... just about any distributor-driven system.

An HEI is similar but it has the amplifier self-contained.

A GM HEI in proper working order is a very good & reliable distributor & will provide plenty of wallop for all but the most radical street motors. They're relatively cheap to acquire, easy & cheap to maintain ... parts available anywhere. I have several; why just today acquired another new take off HEI from new ZZ4 crate ... shop's customer was going to run TPI w/ new ZZ4 and "old reliable big cap HEI" won't work with the computer that goes with TPI.
JACK:gap

 

[rgtrough]

Much Thanks

WOW, Thanks for the imput on the ignitions. Now all I need to do is made a decision. Thanks for being here for guys like me.:cool