This story begins with a 400 sbc that I had the local machinist put together about a year ago for my project k10. It was given to me from a family friend. Before I sent it to the machine shop, I stripped it bare. Fast forward a year, its a clean new 406 with all the bells and whistles. Here I am putting it into my k10, where this week I was trying to install some mechanical gauges. When I got around to the oil pressure gauge, the block wasn't tapped for 1/8in or 1/4in. Upon further inspection, the pitch is very tight, almost metric.
What I have concluded is that the pitch is somewhere around 3/16 or whatever its equivalent may be. The best part of this is I went to napa with the sender and they had never seen that bushing deal before. The people at napa and myself thought it was maybe HeliCoil, but the pitch is far off, and they couldn't find what the pitch was either. My theory is that the people that had it before my friend must have stripped the threads, tapped it with god knows what, and used this bushing to fill that in.
My theory doesn't amount to much because I still have to find a way to get the hole filled and have working gauges. Here are the options I have come up with:
1.) Find a way to tap the whole to 1/4in, without allowing shavings to enter, and adapt the 1/4 to 1/8
2.) Find a way to remove the bushing nonsense and put it on the mechanical gauge fitting
3.) Find a replacement for the bushing (If they did it how long ago, why can't I find a way?)
Any thoughts on this? Have any of you seen this kind of thing before? I'm dumbfounded and after about a week straight of searching I haven't come up with anything useful
What I have concluded is that the pitch is somewhere around 3/16 or whatever its equivalent may be. The best part of this is I went to napa with the sender and they had never seen that bushing deal before. The people at napa and myself thought it was maybe HeliCoil, but the pitch is far off, and they couldn't find what the pitch was either. My theory is that the people that had it before my friend must have stripped the threads, tapped it with god knows what, and used this bushing to fill that in.
My theory doesn't amount to much because I still have to find a way to get the hole filled and have working gauges. Here are the options I have come up with:
1.) Find a way to tap the whole to 1/4in, without allowing shavings to enter, and adapt the 1/4 to 1/8
2.) Find a way to remove the bushing nonsense and put it on the mechanical gauge fitting
3.) Find a replacement for the bushing (If they did it how long ago, why can't I find a way?)
Any thoughts on this? Have any of you seen this kind of thing before? I'm dumbfounded and after about a week straight of searching I haven't come up with anything useful
