I'm wondering because I'm planning on purchasing a transmission
and most of the listing for a 4R70W or grand marquis/crown victoria transmission won't fit the police model.

One thing I've heard is the tail shaft length is different.

Here's an example:
http://cgi.ebay.com/ebaymotors/TRANSMISS...=item1c0f29375c

Thanks.

Pretty sure there is no difference. Someone will chime in with a definite answer though.

Retail model CV/GMQ use the 'short' tailshaft housing and output shaft


CVPI, Town Cars and Marauder use the 'long' tailshaft housing and output shaft


In general, a retail model transmission will work in CVPI (same or compatible model year), but you will either have to swap to the steel d/s - or swap your old extended tailshaft housing and re-use your aluminum CVPI shaft. (If you do this, you also need to plug the small vent in the middle of the CVPI d/s slip yoke or you will have a tiny ATF leak when used with the short output shaft)



What year is your car?


2vmodular has a ton of year to year transmission info here;
https://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=1295031#Post1295031

It's 1999 CVPI

You can use the shorter tailshaft transmissions in a car that came with a long tailshaft. As stated, use your longer housing with it though.

But. lets also make it very clear that you cannot use the longer tailshaft transmissions in a car that had the short tailshaft unless you replace the driveshaft to match. It's very bad having not enough clearance in the driveline. VERY bad.

Darrin

Interesting read. Thought there were differences with the transmissions as well until I spoke with drock.... I had known about the different output shaft and tail housing......as well as the output shaft for civilian being 8 tooth while the CVPI output shaft is 7 tooth.

So really the only differences are the flexplate and torque converter. I am already running the CVPI aluminum driveshaft with my civilian short output shaft and short tail housing and there seems to be no issues. I have been running it like that for a year as a matter of fact.

The only thing to do is thet the CVPI torque converter and flexplate to match and I think I will be very pleased with this car......running the P71 PCM and the civilian torque converter makes for some interesting shifting at times......a bit confused I suppose since it is programmed for an entirely different torque converter.