Hi--
Another potential problem with LED wedge-based bulbs (like the T-3.25_2821/194 bulb)
: many have their wire contact leads wrapped from one side of the base to the other, maintaining an end-to-end polarity difference. But on our cars, the polarity difference is from one side of the base to the other. An incandescent bulb has it's contact wire on one side of one end with the other wire on the other side of the other end.
If you try an LED bulb with a contact wire on both sides of the base it will simply blow your fuse. For the ones I used, from Superbright, I needed to bend each contact wire so it was on just one side of the base (and, of course, the other wire was on just the other side of the base). Now they work fine.
I will also comment that for the colored indicator lights, 5 Lumens is ample light output (or a colored bulb that has 5 lumens for it's white companion's output). 35 Lumens is ample for the instrument backlighting bulbs. Note, too, that if you have a red oil pressure indicator light and you want it to be amber, just purchase an amber LED bulb (it produces no red light so only amber will shine through the lens).
Finally, the "T-3.25" is actually the bulb diameter, expressed as "3.25_1/8th's of an inch". This is also 1CM or 10mm, the common European size. If a "194-equivalent" LED bulb is 10.1mm in diameter or larger it will not fit everywhere in your instrument panel, especially near the speedometer and tach. Since Superbright has bulb dimensional drawings (look carefully for photos or links in the specifications), you can tell what will fit or which may fit if you file away some of the plastic supporting the internal LED mounting board.
Good luck; I like my LED's!
Larry