I'm looking for a thermostat housing for an '87 5.7 that comes with a sender port built-in. The only ones I can find are for the 5.0 and they apparently aren't compatible. I've checked Hawks, eBay, Amazon, Google, etc. Does anyone have a source? TIA

Are you looking for one with npt for tvs ?
like dorman 9022015 ?

Yes, but not for TVS, just for an aftermarket temp sender. That Dorman one would be perfect, but everywhere I check for it indicates that it doesn't work on the EFI 5.7.

If you have tpi I haven’t seen the housing your talking about , if tbi probably would work but I think tbi was introduced in 88 on f body.

If you have tpi just delete the ninth injector and use the timer switch location.

Yes, TPI. I've wondered about deleting it, but it seems to be functioning, at least it seems to have the correct currents when on/off. I can search on how to delete it, but will it affect anything, like starts or throw a code?

Csi is a independent circuit from ecm. No codes if deleted. To fully delete you can upgrade ecm tune to 89

Fortunately my '87 was already converted to MAP. Newer ECM, MAP, ERG delete, etc. No MAF and related relays. So the 9th injector delete should be easy.

The 9th injector wouldn’t be needed if still there. If 85-88 intake you will have the timer switch hole to install your new sender you were looking to do.

Yes, the 9th injector is still there in the older manifold and functioning. I'll delete it. Great to hear! The location for its switch is perfect for the sender I want to install. Thanks for the info!

Perfect! And reasonable price! I ordered it. Thank you!