I have westfield rear uprights, and I believe I can use either the sierra or golf (MK2 i think) rear caliper.

But as the general rule of thumb people use the sierra (i think - doing a lot of thinking today), before upgrading.

But what are the major differences, which one is lighter, can the golf ones use the ford discs, spare parts availability/cost, look on the car, piston/bore size.

Is one option easier to upgrade from. My assumption would be that they are both the same

What are the upgrade paths to consider in the future?

I dont know about what calipers you should use, but from my golf days the Mk2 people swapped the rear calipers to mk3 as they were less prone to siezing up (iirc). I think the mk3 had a better handbrake mechanism. Hopefully someone may remember more about it.

The search will help you
one thread

yep its Mk3 calipers youll be after, (well actually its most VAG cars after a certain year i believe)

I got mine off an audi A4. and i am using them with a BMW 280mm disc. Havnt been on the road with them yet but the setup goes together nicely on the car.

Not mk3 unless its a cab version with the mk 4 front end.
As i said in the link ANY VAG golf, polo, lupo, seat leon, ibiza, audi a3, a4 and so on AFTER MID 1998 IS WHAT YOU WANT

Sierra or Granada ones reason is the VW Golf (and every other hatch back) have much smaller bore rear caliper.

Istr Sierra and also MGTF are about 41mm bore.

Golf and nearly every other medium to large fwd car (even quite big car such as the Rover 600) are around 33mm bore

m8kwr

Westfield rear uprights are machined to different off sets for the calliper mounts so you cant put golf brakes on to a sierra cast up right even though its looks the same
the rear disc's come from a mk3/4 escort and need to be used with westfields hub as it is a smaller diameter than the ford 1 and is also ali not steel


Hope this helps

Richard