OK,I think you are correct with the stock intake having a 1/8" NPT thread sending unit hole.Also correct with the probe having a 1/2" NPT adaptor.I have attached a couple of photos showing I would need approx 1 1/2" deep adaptor(s) to have enough depth for the proble.I would also need an adaptor or adaptors to reduce down the 1/2" NPT on the probe down to the 1/8" NPT hole in the intake.