When I did my swap a few years ago, I was getting 15.5mpg out of the 93 IC motor with the 518. It had steadily declined and I was disappointed when I checked it all the way to Washington and back. 1,300 miles and I was getting 12.5mpg! I was thinking injectors or trans but apparently it was the trans. I lost the flexplate a few weeks ago and decided to just do the whole enchilada.
Spec Rite converter, GPZ clutches, Trans Go shift kit, Steel planetaries, and all the other cool stuff accept for billet shafts. Well, got her in last week just in time for a 170 mile trip. I was pretty excited to see where it was at but I had no idea it would be a 7mpg increase. 19.57 mpg and I wasn't going too easy on her. Feels great to finally be double what the 460 was getting (9.2) and to have a 750 mile range.
The trans shifts really good and firm but the 2-3 shift kinda throws you forward before it throws you back in the seat. Had a buddy drive it and he said it was probably the 2nd gear band needs adjusted or the apply spring is too heavy. I,m either getting used to it or it's breaking in a little. Any advice on this?
Also, the TC is a huge improvement. It helped drop some R's at idle and at cruising speed. My truck has 4.10's and freeway driving was a bit loud. The new TC makes it feel more like my work truck with 3.73's and my foot isn't buried going 70mph or up hills. The egt's climb a lot faster though, so I guess I should be looking at a better turbo. Any suggestions?
Here's a few pics and a video from a few weeks before the flexplate went.
Click for video. It's a lot steeper than it looks.