Stock oil pressure sender thread
 

...is 1/8" BSPT.

Most aftermarket gauges come with 1/8" NPT senders, there's a 3-way adapter on eBay that allows you to keep the stock sender or you can just get an NPt to BSPT adapter from here:

http://www.airlines-pneumatics.co.uk...derCode=103359

Took me a while to find this info the other day so thought I'd share :)

...don't forget PTFE tape!

Thanks mate it's very usefull.

If i remember is: motor>NPT female thread>90°NPT male to BSP female>oil sender with BSP male in our car.

Fantastic. Been after this info for ages. Nice one :D