Belltech 3120 drop spindle fit my truck?!?! Have 30 minutes to decide.

[GAc10boy]

Amazon has Belltech's 3120 3" drop spindle for a really good price and I had some Amazon credit so I hastily pulled the trigger. They are for the 1.25" rotor which I'm not exactly sure if I have.

Can anyone tell me what likely came on a base model 4.1L/250 6 cylinder 1/2 ton truck in 1971? I know that's a long shot but I have 30 minutes to cancel order and won't be home for another hour to check.

[SCOTI]

Originally Posted by GAc10boy

Amazon has Belltech's 3120 3" drop spindle for a really good price and I had some Amazon credit so I hastily pulled the trigger. They are for the 1.25" rotor which I'm not exactly sure if I have.

Can anyone tell me what likely came on a base model 4.1L/250 6 cylinder 1/2 ton truck in 1971? I know that's a long shot but I have 30 minutes to cancel order and won't be home for another hour to check.

1" rotor option didn't start until the early 80's (after the switch to square headlights). The problem is, you need to know it's the original parts under the chassis that weren't ever swapped.

[GAc10boy]

Originally Posted by SCOTI

1" rotor option didn't start until the early 80's (after the switch to square headlights). The problem is, you need to know it's the original parts under the chassis that weren't ever swapped.

This is very helpful! Thank you. Supposedly the truck is all original so I'm hoping that's the case. I did try and go take a rough estimate with the wheel on and a household tape measure and got almost 2 inches. I'm thinking the angle I was holding the tape, etc might've played into it. They are definitely larger than 1 inch and look like factory suspension.

[SCOTI]

Seems like the 1" lt duty option started in 81 or 82.

[GAc10boy]

Originally Posted by SCOTI

Seems like the 1" lt duty option started in 81 or 82.

Just to quell my craziness, ever heard of a 2" rotor on these trucks?

[SCOTI]

Originally Posted by GAc10boy

Just to quell my craziness, ever heard of a 2" rotor on these trucks?

No.

[Tx Firefighter]

Relax. If you have a 71 model truck, you can basically rest assured you have the 1.25 rotors.

If your truck was a factory drum brake truck that had been converted to discs in the past, you might have some reason to worry. But your truck came stock with discs and they were absolutely 1.25 thick rotors stock. The chances of someone swapping to later model spindles and rotors are very slim.

[SCOTI]

Originally Posted by Tx Firefighter

Relax. If you have a 71 model truck, you can basically rest assured you have the 1.25 rotors.

If your truck was a factory drum brake truck that had been converted to discs in the past, you might have some reason to worry. But your truck came stock with discs and they were absolutely 1.25 thick rotors stock. The chances of someone swapping to later model spindles and rotors are very slim.

I agree..... Just CmA-ing it

[lolife99]

Originally Posted by SCOTI

Seems like the 1" lt duty option started in 81 or 82.

I agree.
Never knew why though.
Some 81-87 trucks had HD rotors,... some had light duty rotors.
Was it a GM supplier issue?
Specific to a certain assembly plant?
Why would you offer two different spindles, and rotors???

[SCOTI]

Originally Posted by lolife99

I agree.
Never knew why though.
Some 81-87 trucks had HD rotors,... some had light duty rotors.
Was it a GM supplier issue?
Specific to a certain assembly plant?
Why would you offer two different spindles, and rotors???

I would bet it was mostly to generate additional revenue.

Put the cheaper parts on & charge for the heavier duty stuff depending on how the rest of the drivetrain was optioned. Likely, the straight 6's. v-6's, & 305's got the lt duty parts w/the HD 1.25" rotors the option.

[GAc10boy]

This is all really great info! Thanks for clearing things up for me. This is the main reason I love this forum!