HEI Install Complete

[3 on the tree]

Finally got my HEI dist swapped in tonight. Someone has already run a hot wire for this, so that part was done. Took me longer to sort thru my plug wires for a close enough set than it did to drop the dist in and fire it up. I had forgotten what an easy upgrade this is, been 20 years since I did one.

[jakeslim]

Good! Amazing what this does for performance

[28buick]

If you need plug wires get a set for a 1975 corvette. They are direct fit for center dump cast iron manifolds with GM HEi distributors. The exhaust manifolds for my 72 blazer and 75 corvette are interchangable. When I upgraded the blazer distributor to HEI the vette wires fit perfectly.

[69stepside4x4]

I am about to replace mine but do not know how difficult this actually is. Could someone give me a "brief" tutorial in what is involved in going HEI? I'm a freakin' university scholar/Dean whose built several trucks over the past 20 years (2 of which got national magazine coverage), but I am new to the mechanical workings of Chevys (yes, I am a shameful convert, but I have seen the sins of my past and can only ask forgiveness).

I purchased a Mallory HEI distributor and wires before I moved to London a year-and-a-half ago, and now that I'm back, want to put the thing in. My local shop wants $200 in labor to do it and that just isn't going to happen if I have any say about it. I know how to bring the #1 cylinder up and then pull the dist. out, but I have heard confusing things about the plug wire order being different on an HEI (this may not be true).

Thanks for your help and God bless the USA and 1st generation Chevrolet Blazers!

Mac

[krue]

You need to check out our FAQ board, lots of good info there.

[3 on the tree]

Originally Posted by expat atlantan

I am about to replace mine but do not know how difficult this actually is. Could someone give me a "brief" tutorial in what is involved in going HEI? I'm a freakin' university scholar/Dean whose built several trucks over the past 20 years (2 of which got national magazine coverage), but I am new to the mechanical workings of Chevys (yes, I am a shameful convert, but I have seen the sins of my past and can only ask forgiveness).

I purchased a Mallory HEI distributor and wires before I moved to London a year-and-a-half ago, and now that I'm back, want to put the thing in. My local shop wants $200 in labor to do it and that just isn't going to happen if I have any say about it. I know how to bring the #1 cylinder up and then pull the dist. out, but I have heard confusing things about the plug wire order being different on an HEI (this may not be true).

Thanks for your help and God bless the USA and 1st generation Chevrolet Blazers!

Mac

Mine is a 6 cylinder, but the basics are the same. I don't bother with moving to #1 TDC, just put the vac advance in the saame position as the original and the rotor in the same position as the original. The initial timing will be a little off, cause the terminals are spaced further apart on the big HEI cap, but it will start with a little gas pedal pressure. Have someone turn the dist till it will idle, then put a timing light on it with the vac advance plugged. I did this by myself, so it died a couple of times before I got the timing close enough to idle. I don't know why the firing order would change between distributors, never seen that, but I don';t know everything

[72gord]

Firing order is the same, points or HEI, just mark your number 1 wire in relation to a place on the intake before you remove the old distributor and start with your #1 wire there on the HEI, should be no problem as long as you follow the firing order in the right direction around the cap and get the distributor back engaged in the cam gear in the same place you pulled the old one out of. Small Block firing order is 1-8-4-3-6-5-7-2 and I believe the rotor turns clockwise.