Any experience with Rennline short shift kits or any other short shift products? Thanks in advance.

Are you looking for a "short shift kit" or are you looking to clean up your sloppy shifting?

IMO, no value in the former, and this takes care of the latter:

Tangerine Racing Shift Linkage Kit, plus
Shift Rod Bearing
http://www.tangerineracing.com/transmission.htm

I installed a similar unit to the rennline in a 914 around 40 years ago. It only improves the fore and aft, not the side to side. It will not fix a sloppy shifter, seals, ect.
A little bit of a pain to heat up the base to remove the old shifter and then glue the shifter to the new base. I recently bought a Weltmeister short shifter for one of my cars, which came with the whole shifter and base. This is an easier swap if you can find one. Do a WTB in the classifieds, someone might already have one installed.

I have the Rennline short shift, its good, but I also have the Stromksi coupler and all the Tangerine parts!

Are we talking about this (tail shifter only)?

https://www.rennline.com/Rennline-Short-Shi...tinfo/S-98024P/

If so, I would convert to side shift and get the Tangerine stuff.

Thanks for the input. I have a '74 so this might not even fit anyway?

Yep, that's for a tail shifter. You either need the Rennshift https://www.jwestengineering.com/914-Transmission_c_14.html or the NLA Weltmeister short shift. https://www.pelicanparts.com/More_Info/SHSS...?pn=SH-SSK-9001

I have run a stock shifter in my 75 side shift 2.0, a Weltmeister 914 short shift and now the the Rennshift all with the stock linkages and bushing in good working order.
None of the shifters will take the slop/ play out of the shifts due to poor bushings.OR worn components
They will however:
1) Shorten the distance the shifter ( at the knob) has to move between shifts. Even more so than just shortening the shift handle (which both short shifts do,) but change the throw ratio
2) Lock out for reverse (Renn)
3) Spring loaded "gates"/lanes for R/1, 2/3, 4/5 (Renn) adjustable tension too (Stock) only R/1
4) Over shift shops (Renn)
5) Changeable handle lengths (Renn)

I am very happy with the Renn shifter and would not change back

I have the Rennshift in my car and would not switch back. Only reason for the Weltmeister one is if you do not want to pay $595 for Rennshift or are looking for the look of a stock shifter. I've seen the Weltmeister one occasionally show up in the classifieds for under $100.00

I like mine and it's on a '74.

It has two set-ups IIRC 60% and 40% of the stock throw. I'd start with the 60% and get the feel for that first.
You still can't speed shift it into the gears, that's more the 901 (914) tranny issue than the shifter, so you have to slow down your shifting a little bit. Also I have trouble shifting into 1st from a dead stop, I learned to take my foot off the brake while shifting into 1st.
My 914 is a 3.0/6 conversion, so I only have to use first as a granny gear if I'm stopped on a grade.

I wish the reverse lock out (option, included) had a knob trigger, because with the lock out you have to use two hands to shift into reverse. That said I didn't add the lockout option and I've never hit reverse.

Over all I like the Rennshift, way better shifting and I like that the knob sits further back than stock, but mainly because of the tranny it's not perfect.

Sorry, I meant to say I have the J West Rennshift not the Rennline ball joint!

Same, I have a J West Rennshift as well.