I would seriously suggest not doing that. If you run too high of a gear with your OD then your car would be running so low on rpm's that you would not be able to sustain freeway travel. AMC was notorious for doing this in the 80's and it made the OD's useless I dont know how many AMC's I saw with a t5 and 3.00 or 2.89 gear ratio(my cj7 had this ratio and sorry to say it had a factory posi unit in it too) . Granted yes when I was doing 65 on the freeway my engine was only running about 800-1000 rpm's but I would have to downshift everytime the freeway raised up a little(you know like an overpass) otherwise the engine would bog down and die. If you are going to go with an od transmission you would be better off to look at something atleast in the 3.54 gear ratio to properly utilize the OD.
Yeah, okay. I'm not married to the idea of a 3.00 rear gear with a .68 overdrive. Even though 302 mustangs used a 3.08 rear gear with T5. I just meant a 250 would be happy a lower rpms than say a 200. At 70 mph with a 26" tall tire, 3.00 rear, and a .68 overdrive I'd be looking at around 1800 rpm. paulie
I did a T5 swap into my Ranchero with a 200 and 2.79 - 8" rear with 195/60x15 tires(short). I was doing 65+ before I could put it in 5th and have any ability to maintain that speed. Additionally, the V6 T-5 has a better 1st gear for your inliner. The V8 1st gear is too tall because the V8 has much more torque. You do not need a T-5 bell housing to make this work. I used a top loader bell with an adapter so I could use the stock clutch linkage. With the V8 or late bell housings you will have to make up a cable or hydrolic set up. It's available from the rustang parts guys as is the trans to bell housing adapter, but I like the simple stock parts when available rather them modified parts. Here is a thread on the Ford 6 site that may also help: http://fordsix.com/forum/viewtopic.php?t=50854 I used a 4cyl mustang clutch with the stock falcon flywheel and T/O bearing as well. For a 250 I would stay away from the 4 cyl T-5. The 6 cyl T-5 is actually a bit stronger then the V8 as it has larger input shaft bearings and a longer input shaft that will need to be turned down/shorter. I did love the swap. It was a great change from the 3 speed to a 5 speed.
Never checked it. MPG was not the goal. I had decked the block & head .040, large valves, some porting, V8 springs, flat top pistons, Isky 262 cam and a Holley/Webber two barrel carb. Blew away a friend 289 Mustang to 80. However, before the swap the top speed was about 75. So between the engine, trans and rear end this became a really fun car. I sold it to help my son with his project, but I really did like the set up. If I had to guess, it was getting 20mpg + based on a 120 mile trip I took when it was done. I've tossed around the idea of doing this to my Mav. Have all but the tranny to do the conversion.
I have a 73 250 4 door...would my gear ratio be 3.00? i know that a 73 grabber v-8 is 2.79 so Im guessing mine would be 3.00?
My tag on the side of my door rubbed of...I assumed that since the 73 v8 grabber had the 2.79 i thought my 250 would be 3.00?anyone here have a 73 250 automatic four door that can confirm this?
Your 73 four door?Did it have the 250?My machinist wanted to know cause hes rebuilding my engine and he wanted to know the gear ratio to figure out what cam would be best for me
Your 73 four door?Did it have the 250?My machinist wanted to know cause hes rebuilding my engine and he wanted to know the gear ratio to figure out what cam would be best for me