Stay away from Marshall Instruments
I got a used NOS system which included a pressure gauge from Marshall Instruments along with a pressure sender that mounts in the trunk. I bought an extra wide band gauge from them - which of course didn't look like the nitrous pressure one I had - they've changed model and I was stuck with the ones that I got. Thanks Marshall - way to treat your customers.
I read the instructions carefully (which I always do since I met my wife) and mounted the manifold on the by the retailer recommended spot. When adjusting the heater pressure sender I heard a large BANG and my head started hurting like crazy. The entire bottom part of the pressure sender had blown and parts of it was jammed in my forehead. I had to go to the ER and remove them and ended up with a few stitches. Thanks Marshall for being understanding, asking how I felt and if everything was alright with me... or wait - you still haven't checked up on me. Way to treat your customers Marshall!
I contacted Paul at Marshall instruments who first agreed to replace it AND refund me but later changed his mind to just replace it which didn't happen until I contacted them over and over again. The reason for the delay was plausible - they wanted to make sure that the new ones from another manufacturer were alright.
Then the new sender arrived - and it showed NO signs of being tested before it was shipped to me. The teflon paste in the threads were perfect, and showed no signs of being refilled after testing. There were no scuff marks on the nut and the harness connections showed no signs of being test mounted. Way to go Marshall - tell your customers that you tested the particular unit that was sent when it's obvious that you haven't. Lying doesn't get you far when it comes to customer relations.
Of course the new sender didn't work - once I opened the bottle - the gas shot right through the sender... Again I contacted Marshall Instruments, but this time I was told that it was my installation that was the problem (I've checked with nitrous outlet who says that I've done my homework and that the sender is broken) - and they won't send me another one since they've already sent me one. Thanks Marshall, now I've ruined two fine bottles of gas AND I still have to buy an Autometer sender, way to treat your customers...
Please note that the particular sender was NOT bought from Nitrous Outlet, and they (NO) has been more than understanding - I would recommend them (Nitrous Outlet that is) to my own mother.
Marshall Instruments however - I would NOT recommend to anyone. Their customer care is terrible, their attitude towards customers is rotten and their products have serious quality issues.
Stay away from Marshall Instruments!