question on hei install

[dyingdeadman]

I was wanting to do the hei conversion on my 72 with a 402 big block but am a little unsure as to which hei dist to get or will work. I was checking my local parts store online and found this one that says will work for a 75 gmc with a 454 so would it work for my application?

the link didnt work right but the dist i was looking at is a accel part # 59107
it is on advance auto parts web site
also what all do I need for the conversion. i know i will need some wire and an inline fuse and new plug wires. but do i need anything else.

[lofly'a]

the link took me to the parts america homepage, and i didn't do a search, but as long as the hei is for a bb from 74 to about 80 you'll be fine. you'll only need a 12 volt source that is "switched" from the ignition (energizes when the key switch is turned on). you'll find one in the fuse panel to hook up to labeled "ign". don't use a fuse, and don't hook up the wire from the hot side of the coil to the hei because it does not put out a full 12 volts (about 7 to 9 volts at most) tape the end of that one up. it'll run that way, and i've seen quite a few hooked up like that but it'll stumble and backfire under acceleration. get the right gauge wire also, 12 gauge, get the plugs for that year engine and gap them for that year, and hook up the spark advance.

[dyingdeadman]

thank you, just the info i was needing.

one more thing, what is the spark advance? and where does that hook up to.

think i need to read through the faq pages again.

[dyingdeadman]

ok I read through the hei stuff again, and i think i got the install all figured out. but had a question about the spark plugs. couldnt i just use the plugs for my year of truck and gap them to 45 for the hei?

[Tx Firefighter]

loflya gave you a little bad information.

The HEI distributor is the same whether the engine is a small block or a big block. You don't have to buy one specifically for a big block. I learned this a long time ago.

Don't believe me? Check Summit or Jegs. You'll see them cataloged as fitting both small and big block engines.

[GMC AMI]

Tx is very correct, they are absolutely the same. The Hei needs a full 12 volts on start
up the most. That is the most important reason for not using the original points dist. resistor wire.

The spark advance (aka vac. advance) hooks up via the vac. rubber hose from dist. to carb. proper port.

[dyingdeadman]

thank you.

I bought all the stuff today I need to do this. now if it would just stop raining so i can put it in.

[lofly'a]

i knew that TX firefighter, come on, not bad info, just forgot to mention it. thanks for the clarification. guess i was more focused on the install than the application cuz i've seen quite a few bad install frustrations and as long as he got one before the crappy early 80's electronic controls were added and spark advance deleted. the spark advance is the diaphragm canister that sticks out the side of the distributor. do use plugs for 74 up hei bb system.

[dyingdeadman]

ok got the dist in, this might sound stupid but where do you put the # wire on the cap? and do you install the wires clock wise or counterclockwise?

[Tx Firefighter]

clockwise, 1-8-4-3-6-5-7-2.

[dyingdeadman]

thank you, but does the #1 have to go to a specific place on the cap or can it go anywhere as long as it is in that order?

i put the distributor in and and did use that firing order, when i tried to start it. it tried to start but just wouldnt start then i moved the dist a little bit clockwise and it backfired through the carb. so do i have it in backwards or maybe off just a notch or something.

[smokekiki]

Could be off 180.Best thing to do is remove #1 plug,which is the drivers side front.To Find top dead center place your finger over the plug hole while somebody bumps the starter.When the line on your damper is coming to the tdc mark,if on the compression stroke it will blow your finger off the plug hole.Line up the mark and line.Your rotor should be pointing at the #1 plug hole.If not pull dist and put it back in pointing at the hole.

[smokekiki]

When standing at the front of the engine,use the front post on the drivers side as #1.It should point towards the #1 plug.I have my 72 suburban with stock 350 set at 8' btdc.

[lofly'a]

yea, what they said, ................and......to make the dist. install easier line the rotor up to where #1 is on the cap, turn the dist. upside down and look at the bottom of the dist. to see where the oil pump extention shaft lines up down in the block, then get a long screw driver, and a light, and positon the oil pump shaft down in the hole to match the same position when you install the dist. it will not seat flush with the inake until the shaft ends line up.