What size Tel-Tru?

I'm getting ready to order a Tel-Tru BQ300, but I'm conflicted on what size to order. I'm planning to mount in the lid. I figure the 4" will give a closer temp to what's at the cooking grate, but someday I plan on smoking a turkey and I don't want the stem to get in the way. Any suggestions which way to go?

Thanks in advance,
-Michael

Believe it or not I bought the 5" dial face and after words I thought jeez thats gonna be to big..But I love it big dial can see every digit in 5 degree increments..Just buy the 2 1/2 stem

I have a Ashcroft with a 4" stem, perfect length if you drill the hole in the right spot and that will get you real close to the grate. If I ever need another thermo, I'll be getting me a Tel-Tru.

I bought the 3" dial with 2-1/2" stem (Tel-tru BQ300). I thought that any longer stem might get in the way of the meat. I also have my ET-73 to measure the grate temperature.

MikeZ

Personally I feel that a thermometer having a 5 inch face is way too large for your application. Not that much precision is needed in reading temperatures; and, unless permenently mounted, a thermometer having a 5 inch face is much too weighty. Get yourself one having the 3 inch face with a 2 1/2 inch stem. That size seems to be standard around here.

3" dial with 4" inch stem. Stem has not been a problem with 9 lbs butts or anything else I have cooked. Don't feel like I get as much radiationg heat from the lid using the 4" stem.

I bought the BQ300 with 3" face and 2 1/2" stem. I would say that is the correct size.

Just a note about my own experience: The stem of a Tel-Tru thermometer is scribed with a notch indicating how deep the thermometer must be mounted to obtain correct readings. On the 2 1/2" stem model, that notch is about 1 5/8" up the stem. In other words, virtually the entire stem must be located on the inside of the smoker (the 2 1/2" measure includes the threads of the thermometer).

I followed John McGee's lead by using the Watt's coupler's and found that I had a brand new $40.00 thermometer that read about 100 degrees off (too low). The Watts A177 coupler mounts the thermometer much higher and the scribed mark on the stem will actually be on the outside of the lid. I emailed John and he told explained that he used professional machining tools at work to modify the couplers.
His method looks great, but beware of the required extra effort it will take to get accurate readings.

I followed the McGee method using the Watts coupling and experienced the same problem with the nut inside the lid extending too far and covering too much of the thermometer stem.

I solved the problem by screwing both parts of the Watts coupler together and cutting off the last 1/2" of the unit in a vise. The 2 parts now mate tightly together instead of leaving a gap that previously had to be filled with a washer and also allows more of the stem to be uncovered.