Wild shot but check Ebay for the right 3 3/8 hole saw before you hack it up


2sav

quick check on Ebay and they have the 3 3/8 hole saw but it was for cutting granite.  But they must make a 3 3/8 for wood?


2sav

Last time i did it I got real ballsy(stupid) and did it free hand hole saw no pilot, cocked it at the slightest of angle to get started and then layed it down, came out perfect but I reallized afterward how dumb it was.

But I would typically do what 76 Bonneville said and clamp a chunk of wood in behind the old gauge hole, but I would use an extra long pilot insted to get my center.  U might actually be avble to get away with 3.25 hole saw, alot of tacks/speedos are a little loose in a 3.375 hole.

Like Josh said, use the 3 1/4". That's what my Livorsi 3 3/8" fit into perfect. I ran into the same dilemma and was figuring I'd just use the 3 1/4" then custom dremel it to fit. Well the gauge dropped right into the 3 1/4" hole without any modification...

you can get any hole saw size you need pretty much try toolcrib.com or you could use a rotozip

use blue tape and shouldnt chip or if you get a granite hole saw with tape it wont chip for sure

You take a 2 1/8 hole saw and cut a chunk of 3/4 inch plywood with it. Take the plug out of the hole saw which will be 2 1/16, the size of your hole in the dash and tap the plug in place in the offending dash hole. With any luck it will be a tight fit, if not wrap it a few time with tape and drive it in. then you can cut the new hole in the dash with no worries.

You can swing by my house this Sunday after the LB swap, I'm about a mile from the place, and I can load you up with all the hole saws you need, even one of my old school 1/2 drive Millwakee drills...if you promise to return them. I've not got a few tools back from a few guys over on hot boat over the past couple of years so I don't offer them out as much.

Or you can drag the boat over here and we can do it at my place. 

Thanks oldrigger....i really appreciate the offer.

i did it last night successfully.....I used a 3.25 whole saw and just used the back piece of wood. i re-rigged the mandrel so that the piolet drill stuck out further to reach the backside piece of wood.....then eyeballed the center point marking and measured it a few times from every angel...then drilled....came out perfect. The guage ended up being 3.3"...the whole i was drilling was 3.0".....so after the 3.25" cut, i used a barrel sander to open up the hole until the gauge would only fit if i forced it.....then i hand sanded the hole until it smoothly glided in.

yes, the dash looks like chaos now as you mentioned, but this will only be my 'race' setup. the tach and wheel will be swapped depending on the application (full interior lake boat or  single seater race boat)....here is some pictures....







The whole where the tach sits now will also use a angel bezel to turn it in the direction of the driver. I am aware i will have to cut out more to get the bezel to fit...including the wood that will be displaced by the angel.

Cool.

Didn't know you were building an old race boat. I like the dual foot throttles, never seen that kind of set up before.

the one on the left is the pump for the keg tap 

nah, they arent even mounted in there yet...i was just mockin some stuff up.

 I,ve knew  that Brad is a little different, but never noticed his 2 right right feet.