Vortec distributor difference

[bluex]

I have a GM01 distributor (5.0/5.7) that I have had kicking around for years. I got it cheap as a spare for the Z71 (I think)

I have my dually (7.4) apart for intake gaskets an injectors. I looked over the probably factory plastic distributor an besides the mounting ears for the cap both being cracked the gear has some noticeable wear.

So I pulled my spare out ran the number an saw it doesn't cover a 454. Started comparing an measuring an can't find a difference. All I found with some searching was the 7.4 factory plastic distributor used a special thermal washer to protect the body from the cam gear.

Some aftermarket aluminum ones say the fit all V8s an some have 2 different part numbers, an of course the 7.4 one is $10-30 more. I know with HEIs a V8 distributor fits all V8s so I don't see why these aren't the same, especially with the cap/rotor and cam sensor all being the same parts between the 2.

Anyone actually know what the difference is? I'd love to be able to use this one, save $100+ an prove to my wife my "hoarding" pays off!

 

[tayto]

7.4L Vortec Distributor Suggestions?

Don't have any issues with my truck at the moment that I know of, but I'm wanting to replace the distributor before a very long trip that'll involve, you know, just totally normal stuff like towing a travel trailer for 7,000 miles over 2 weeks and since I know the factory style 'plastic'...

www.gmt400.com

 

[Schurkey]

I have a GM01 distributor (5.0/5.7) that I have had kicking around for years. I got it cheap as a spare for the Z71 (I think)

I have no idea what a "GM01" distributor is.

I found with some searching was the 7.4 factory plastic distributor used a special thermal washer to protect the body from the cam gear.

The 454 Vortec distributors do have a "thermal washer" which probably also means they have a different distributor gear to make room for the additional thickness of the washer.

Best I can tell, the 454 warms the oil enough to damage the plastic distributor housing. Whether an aluminum housing from an aftermarket distributor would be affected, I can't say...but it seems unlikely PROVIDED there's enough end-play between distributor gear and housing. Folks seem unreasonably willing to shim distributors to remove that clearance.

If/when the plastic distributor on my '97 K2500 7.4L takes it's inevitable dump, I have every intention of cramming-in an aluminum distributor I bought from another forum member. It won't have a thermal washer, and I have no plans to put one in.

But that's me.

Some aftermarket aluminum ones say the fit all V8s an some have 2 different part numbers, an of course the 7.4 one is $10-30 more. I know with HEIs a V8 distributor fits all V8s

Well...they're not going to fit "all" Chevy V-8s.
No-one ever considers the first Chevy V-8, from before WW1.
The W-block 348/409/427 takes a different distributor, too.
And speaking of oddballs, there's always the Lotus-designed, Mercury-built four-cam Corvette LT5 engine which if I remember correctly, doesn't have a distributor, as well as the Y2K-ish 8.1L. Coil-near-plug ignitions on both.

For the record, GM hasn't installed a NON-HEI distributor for domestic engines since 1975. They're ALL "HEI", but there are various versions of HEI.

Anyone actually know what the difference is? I'd love to be able to use this one, save $100+ an prove to my wife my "hoarding" pays off!

Far as I know, the "difference" is that thermal washer and the distributor gear.

And that's probably important for Space-Age Composite (crappy plastic) distributor housings. I'm willing to bet that it makes no difference for aluminum distributor housings; the aftermarket selling aluminum Vortec distributors with thermal washers are more monkey-see, monkey-do than actual engineering requirement.

So go ahead and impress SWMBO. That's my plan, too.

 

[bluex]

@Schurkey

GM01 is the part number to alot of 5.0/5.7 vortec distributors.

GM03 is for 7.4

Your post in the above linked thread was the only one I found mentioning the difference. Alot of people in that thread say they like the summit brand distributors. They like most others list one part number for 5.0/5.7 and a different number for 7.4.

My references to HEI interchangeability meant engines that came with them factory an the fact that the vortec series of small/big block engines are still that same family in long block form. So to me the distributors should still be the same. If I wanted to carb swap this L29, I'd just buy a V8 HEI an it would be fine, or I could use the one from the 350 in my C10 that was on the same shelf since I swapped it to efi.

The truck won't be towing heavy anymore, max would be my C10 on an open trailer so the heat isn't an issue I'll be concerned about. I'm actually about to delete the oil cooler too because everything associated with it leaks an for the moment I dont see it being necessary either.

 

[Erik the Awful]

Some aftermarket aluminum ones say the fit all V8s an some have 2 different part numbers, an of course the 7.4 one is $10-30 more. I know with HEIs a V8 distributor fits all V8s so I don't see why these aren't the same, especially with the cap/rotor and cam sensor all being the same parts between the 2.

As I understand it, the Chevy HEI will fit your standard small blocks and big blocks. However, I don't think it drops into other GM V8s. I know the Cadillac HEIs are longer.

 

[bluex]

As I understand it, the Chevy HEI will fit your standard small blocks and big blocks. However, I don't think it drops into other GM V8s. I know the Cadillac HEIs are longer.

Again I'm not talking about anything other than regular small an big blocks that came factory with an HEI when I talk about them fitting everything. Cadillac, pontiac, Buick, rare lt5s etc aren't the same engine family.

Granted my first mention of it was pretty broad but given the subject, I figured most people would understand I meant small/big block engines, not every V8 GM ever made, sheesh....

 

[bluex]

Following up here, I have probably 200 miles on the 5.7 (L31) distributor on my 7.4. It's running great besides being thirsty

 

[mwilliams55555]

Following up here, I have probably 200 miles on the 5.7 (L31) distributor on my 7.4. It's running great besides being thirsty

Yeah they are the same, within types, even with points, a V-8 is a V-8 as far as distributor goes, changed many out,

 

[Schurkey]

Yeah they are the same, within types, even with points, a V-8 is a V-8 as far as distributor goes, changed many out,

They are NOT "the same".

The difference between the small-block and big-block Vortec distributor has already been discussed.

Some of the TBI B-bodies had a special intake manifold and special distributor; the distributor housing was bigger at the intake manifold, which had a bigger hole to drop it into.

Try fitting any Small-block, or Mark IV, GEN 5/6 distributor into a late-'50s, early '60s V8 W-block 348, 409, 427.

 

[GoToGuy]

It would be a model number not a part number. The GM part numbers are usually at eight numbers as GM 10191340. A GM seal.