Temp sender and Shift Linkage Qs.
 

1) I grabbed a new temp sender for my new engine based on my model truck. After looking at the hole for the temp sender on my new engine it is tapped for a much smaller size. Where there multiple size temp senders? If so what should I get a sender for? (like what model) (first pic).

2) I'm a little confused hooking up my shift linkage on my TH350. There is a rod that goes from the column down to the trans. On the trans there is a mechanism that moves up and down for the various gears. What position is park? At first I thought it was when it was flat (horizontal, 2nd pic) but when I hook it up that way I can't cycle through the gears. I reversed it with park in the highest position (vertical, 3rd pic) it would go in and it seems to cycle through all the gears. I hope all of that made sense. I'll attach some pictures.

Re: Temp sender and Shift Linkage Qs.
 

1. you need the correct sender for the gauge. You may need to get/make an adapter to make the correct sender work. (I ended up doing this on my '74 with an '87 engine. Looks like you are in the same boat).

2. you will feel more resistance coming out of park. Sounds like the 2nd way yoiu went is correct.

Re: Temp sender and Shift Linkage Qs.
 

Hmm, the sender matches the one on my old engine. It's for the gauges and not the lights. I might end up making an adapter out of plumbing fittings. Was just hoping there was a different way.

Re: Temp sender and Shift Linkage Qs.
 

That's what I ended up doing. The guys at NAPA let me rummage around their bins until I had something that worked. Not pretty, but it worked. You could try using the later model sender; it might work.

Re: Temp sender and Shift Linkage Qs.
 

The smaller diameter sender used on later '80s engines is not calibrated for the 74-78 temp gauge.
I've read about guys turning the threaded portion of the '80s sender down in a lathe and re-threading it to match the later model metric sender on the LS engines.
You might be able to drill out and re-tap the sender boss in the cylinder head. I'd be extremely careful to closely examine that boss... to ensure there's enough meat in the casting to get away with that.
You could put the 74-78 temp sender in the intake manifold coolant crossover heater hose connection and live with the fact that it runs slightly cooler there.
You could swap in a 1979 temp gauge and use the smaller diameter 1350 ohm 1980's sender in the head.

Re: Temp sender and Shift Linkage Qs.
 

I had the same problem when I put a later model 400 in my truck, I used the sender out of my old engin and the only place I could locate it was in the thermastat housing.

Re: Temp sender and Shift Linkage Qs.
 

I had the same issue with my crate engine. I got a sending unit to fit the new engine. My gauge works but it doesn't show as hot as it did originally. Since my gauge has marks and not numbered I've learned to live with it. The one time that it got hot (deer antler in the radiator) the needle moved on over like it should.

Re: Temp sender and Shift Linkage Qs.
 

I bought a adapter in pipe thread for the head,works great