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The '68 C3 did have a rectangular ballast resistor mounted to the firewall. GM went to the 'built in resistance wire' in '69. If you have original wiring harness in your '68 car, it does NOT have a resistance wire built into it.
1967 is the last year for a firewall mounted ballast resistor for Corvettes. 1968 was the first year model Corvette that used a resistor wire from the engine side of the fuse block to the coil. My original owner 1968 Corvette came this was from the factory in FEB 1968.
When you go to the HEI, you will want 12V going to the coil. The best way is to put a terminal end on a wire and plug it into the IGN post on your fuse block. Run that wire out through the firewall and put a terminal on the other end to plug into the HEI.
Good information. When I hooked up the HEI for my 1970 Corvette that came in my ZZ crate engine, this is the way I put 12 volts to the HEI, real simple with plug connectors on each end.
You all have provided some excellent info! Thank you! My HEI should arrive today. I plan on hooking it up this eve...looks like a simple install. Do I need to increase the spark plug gap to 45? I'll post as to if it works Thanks again for every ones help!!
Alan
1967 is the last year for a firewall mounted ballast resistor for Corvettes. 1968 was the first year model Corvette that used a resistor wire from the engine side of the fuse block to the coil. My original owner 1968 Corvette came this was from the factory in FEB 1968.
I was surprised that Accel was offering a point eliminator kit that was exactly like the old Mallory Unilite system. Back in the late 70's early 80's when the Unilite was first offered it was a complete POS and quickly gained a reputation of bad reliability.
I myself won't trust an optical triggering system and stick with Hall effect systems like the Pertronix Ignitor.
Use an Ignitor II or III system and you won't have to worry about ballast resistors and other components that may also be failing. I don't think you can beat an Ignitor III system with a 0.32ohm coil, the spark is hot and the rev limiter is built in and easily adjustable.
I also have the Ignitor III with the Pertronix 0.32ohm coil in my LS5, works great.
If I cant get the HEI working I'll go with that instead...dang car.....wearing me out Oh well....I'll get to work on it tomorrow after work......
thanks!
Alan
Hello,
yea! Got it running! Runs great except when I hook up the vacuum advance the engine speeds up id say 1000 rpm??? Without the vacuum advance hooked up car runs great??? It did not have a vacuum adv. on the distributor I replaced. Any help is greatly apprecialted.
Thank you!
Alan
I am glad you got it running.. .the tough part is getting it to run right..not really but when your frustrated it can only make it worse ..what I do if I having a problem that is driving me nuts is usually smash the trash can next to my box and throw a hammer!....nah...just kidding..made you laugh though..I hope..what you describe is idle increase with the vacuum advance hooked up..sounds like you may have an adjustable advance? If you have one it may say it on the install directions it came with...oops I said directions..lol..it is usually changed with a small allen head wrench that you stick in where the vacuum plugs into..it may be set to the lowest setting..if you have time also I would read over the sticky on how and what you need to set the timing right on..this is a guess on the vacuum being adjustable..but there has to be a reason why the timing would advance when you hook up the vacuum..you should be able to verify it with a timing light! Have fun! Sit down and relax a little..sounds like this one is almost done!
Chromie69,
Thank you for the reply! You did make me laugh...good to have a since of humor when dealing with cars Come to think of it...I think it did come with an allen wrench. I'll have to check and read more of the instructions The engine is a camed up 350 but I have no idea what type of cam the PO put in it? Would this affect timing? I'll piddle around with more and see what I can find.
Thank you!
Alan
Ok so it might have adjustable vacuum..if you pop the allen wrench in there turn it in to increase pressure on the diaphragm ..now..to set this up correctly everything must be adjusted all at one time..from idle mixture to base timing or total advance..I think its easiest to try to go with the sticky on this and if you hit a road block kick the dog and ...no no not that again I am being silly again..post up a q and see what happens..from what I know its snowing out there as it is here so you got time!
Thanks again for the reply So I put the allen wrench in the vacuum port of the advance where the hose goes? I'll give it a shot tomorrow or next day. I'll then check out the sticky. Yup cold out no snow here yet! I'm ready for spring
Thanks again!
Alan