Rotor size - The 1947 - Present Chevrolet & GMC Truck Message Board Network

biddaboy · 05-18-2003, 08:34 PM

I was wondering if any members know what was the last year for the 1.25 inch rotors in a half-ton pick-up.thick that is Thanks biddaboy

gchemist · 05-18-2003, 09:02 PM

Probably all 80's had the 1.00 (typo on the 1.25

) rotors unless it was a special order or heavy duty

**N2TRUX** · 05-18-2003, 09:09 PM

Quote:

Originally posted by gchemist
Probably all 80's had the 1.25 rotors unless it was a special order or heavy duty.

Huh? Do you mean "Probably all 80's had the 1.00 rotors unless it was a special order or heavy duty?
I'm not sure what the years are, but most trucks came with 1.00 rotors unless it had a towing package or "Camper Special" package. Then they were upgraded to the 1.25" rotors...

gchemist · 05-18-2003, 09:12 PM

Oppss, yea typo. Mine has the 1.00 rotors.

**swervin ervin** · 05-18-2003, 09:55 PM

If it has the heavy duty rear suspension, I think they came with 1.25 rotors. I know mine did anyway.

littlebubba · 05-18-2003, 10:01 PM

I have an '81 with 1.25" front rotors. Nothing special about it or HD. Bottom of the line version 6 cyl, stick vehicle. Parts books do list both 1" and 1.25" depending on the spindle. Spindle for 1.25 I am told is longer obviously!

littlebubba · 05-18-2003, 10:09 PM

I have an '81 with 1.25" front rotors. Nothing special about it or HD. Bottom of the line version 6 cyl, stick vehicle. Parts books do list both 1" and 1.25" depending on the spindle. Spindle for 1.25 I am told is longer obviously!

**N2TRUX** · 05-18-2003, 10:09 PM

Quote:

Originally posted by swervin ervin
If it has the heavy duty rear suspension, I think they came with 1.25 rotors. I know mine did anyway.

Yeah, I'm still trying to figure out exactly what option package they came with. Unlike cars today, where everything is grouped together, on our year trucks you could actually order oddball one of a kind things.

My 82 Blazer is a Silverado. It came with power steering, power brakes, tilt wheel, cruise control and even a power rear glass.
It does not have power windows or door locks.

It came with 1.25" rotors too. I just don't know why? I decided to improve things a bit...

78SilveradoSWB · 05-18-2003, 10:38 PM

N2TRUX:

Are those pictured 1.25" slotted rotors? Where did you get those?

ElGracho · 05-19-2003, 12:04 AM

A couple things:

The 1.25" rotors were available at least from 81-87, My uncle's 81 has them and my 87 has them. The option codes that get them are JB5 and JD5 for gas and diesel (vacuum vs. hydroboost) respectively. There doesn't seem to be any options required to order the heavy duty brakes, but you must have heavy duty brakes to order the heavy duty front springs (F60). All trucks that had cruise control had to have power brakes (J50) or the heavy duty power brakes that we are talking about.

biddaboy · 05-19-2003, 12:08 AM

Thanks for all the replies guys you have been very helpful,as usual biddaboy

ocbaud · 05-19-2003, 12:37 AM

Quote:

Originally posted by 78SilveradoSWB
N2TRUX:

Are those pictured 1.25" slotted rotors? Where did you get those?

those are rear disc brakes

nice ones i should add

apstguy · 05-19-2003, 12:40 AM

N2TRUX: I see you have rear disc brakes. If you don't mind me asking, where did you get them and for how much? Did you get matching front rotors?

**Captkaos** · 05-19-2003, 11:04 AM

The HD brakes were standard for Blazer/Jimmys. All of them I have seen have had them, I think the Suburbans are the same way. bigblock73 can check his, but I am betting they are 1.25 also.

As for the last year, it was '87, the last year of the body style.

05-18-2003, 08:34 PM	#1
biddaboy Registered User Join Date: Mar 2003 Location: Port Alberni.B.C. Canada Posts: 149	Rotor size I was wondering if any members know what was the last year for the 1.25 inch rotors in a half-ton pick-up.thick that is Thanks biddaboy

05-18-2003, 09:02 PM	#2
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Probably all 80's had the 1.00 (typo on the 1.25 ) rotors unless it was a special order or heavy duty __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos Last edited by gchemist; 05-18-2003 at 09:12 PM.

05-18-2003, 09:12 PM	#4
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Oppss, yea typo. Mine has the 1.00 rotors. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

05-18-2003, 09:55 PM	#5
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	If it has the heavy duty rear suspension, I think they came with 1.25 rotors. I know mine did anyway. __________________ Mike 1985 Chevy C-10

05-18-2003, 10:01 PM	#6
littlebubba Registered User Join Date: Jun 2002 Location: Clinton Twp., Michigan Posts: 321	1.25 Front Rotors I have an '81 with 1.25" front rotors. Nothing special about it or HD. Bottom of the line version 6 cyl, stick vehicle. Parts books do list both 1" and 1.25" depending on the spindle. Spindle for 1.25 I am told is longer obviously!

05-18-2003, 10:09 PM	#7
littlebubba Registered User Join Date: Jun 2002 Location: Clinton Twp., Michigan Posts: 321	1.25 Front Rotors I have an '81 with 1.25" front rotors. Nothing special about it or HD. Bottom of the line version 6 cyl, stick vehicle. Parts books do list both 1" and 1.25" depending on the spindle. Spindle for 1.25 I am told is longer obviously!

05-18-2003, 10:38 PM	#9
78SilveradoSWB Senior Member Join Date: Apr 2002 Location: Beaverton, OR Posts: 1,615	N2TRUX: Are those pictured 1.25" slotted rotors? Where did you get those? __________________ Mitch 1978 Chevrolet Silverado C 10 454 BB, TH400

05-19-2003, 12:04 AM	#10
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,553	A couple things: The 1.25" rotors were available at least from 81-87, My uncle's 81 has them and my 87 has them. The option codes that get them are JB5 and JD5 for gas and diesel (vacuum vs. hydroboost) respectively. There doesn't seem to be any options required to order the heavy duty brakes, but you must have heavy duty brakes to order the heavy duty front springs (F60). All trucks that had cruise control had to have power brakes (J50) or the heavy duty power brakes that we are talking about. __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed

05-19-2003, 12:08 AM	#11
biddaboy Registered User Join Date: Mar 2003 Location: Port Alberni.B.C. Canada Posts: 149	Thanks for all the replies guys you have been very helpful,as usual biddaboy

05-19-2003, 12:40 AM	#13
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	N2TRUX: I see you have rear disc brakes. If you don't mind me asking, where did you get them and for how much? Did you get matching front rotors? __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

05-19-2003, 11:04 AM	#14
Captkaos www.73-87chevytrucks.com Join Date: Dec 1999 Location: Birmingham, AL Posts: 6,935	The HD brakes were standard for Blazer/Jimmys. All of them I have seen have had them, I think the Suburbans are the same way. bigblock73 can check his, but I am betting they are 1.25 also. As for the last year, it was '87, the last year of the body style. __________________ Chris Lucas 1973 Chevy C-10 1978 GMC Jimmy (2WD) - SOLD 1987 R10 twin turbo LS 1991 R3500 SRW CrewCab 1985 K5 diesel swapped project 1989 K5 2WD conversion w/ Vette susp Project Captkaos Customs 73-87chevytrucks.com

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.