Large Bore Calipers

[gmtofd]

Notice that Speedway lists a large bore caliper #91031040 and their tech assist phone guy says that their a direct replacement for the OEM calipers, which goes by their part # 91031045. Think the piston is 3/8 inch larger od.

Was wondering if anyone out there tried this swap?

Was also wondering what is the story with this large bore caliper? Is it simply a B body caliper? Our pin to pin centerline distance is about 5.25 inch. Have a feeling that the B body pin distance is greater.

Given that there are no changes being made to the braking surface area, wondering if the increased clamping force that a larger bore caliper has to offer benefit to justify the $75 increase a piece price jump?

Thanks for any response.

 

[Hippi]

I have the US brake brand large bore front calipers and it is a bolt in bolt out affair no mods necessary,I have had them awhile and don't really remember how much I paid for them but it wasn't much it sure wasn't over $80.about the stopping power I changed the whole brake system at one so i can't say if there are an improvement over stock.

 

[gmtofd]

Thanks for the response. I'll check out US Brake.

Just wonder if those large bore caliper are just calipers for a B body or a Astro?

 

[LS6 Tommy]

I just posted about this a while back. They're not B-body calipers. They're GM Metric fitment (G-body) with a bigger bore. The B-body caliper works better because it has bigger pads (more swept area) even though the B-body piston is smaller than the oversize metric caliper piston.

Tommy

 

[gmtofd]

Tommy,

B body calipers are a bolt on?

Are B body the same as used on Astros?

Thanks.

 

[gmtofd]

To answer my own question on cross reference, Astro and Bbody are the same calipers.

Are these a bolt on? Would like to do this swap next month on my daughter's Monte SS and won't really have access to my normal tools and such, because I'm flying to where the car is located.

These caliper work with the smaller od G body rotors?

 

[355_79bu]

No, the g-body spindles have a 5 1/2"mount spacing, whereas the b-body has a 6 1/16" mount spacing. Mount spacing being the distance between the 2 caliper mounting bolts.

 

[gmtofd]

Thanks for your help. Not switching over to B body caliper, because that means a spindle swap and the aftermarket uca route. Just going to stay with the stock set-up, except for maybe better pads.