250 and 3 speed in xp falcon

  • Thread starter Thread starter Anonymous
  • Start date Start date
A

Anonymous

Guest
Hi, i bought my xp with a 250 out of an xb with a 3 speed auto and i have two questions. It has origanal diff and screams a little at 100kph and was just wondering if anyone new of a better diff that would fit under and i will be putting on 14 inch rims to help a little. Also i am running the old strongberg carby and its a little guttless and chews the fuel anyway. I was wondering if i should upgrade the carby? The car is also my everyday car at the moment. Thanks to anyone that can help. :D
 
First off, what engine did your xp originally have, if its a 170, then the axle ratio is probably 3.5:1 with 13 inch wheels which will give the screaming you describe.
XPs with the 200 had 3.2:1 axles and if you added 14 inch wheels then that would be near to the XB ratios and much more comfortable.
XP fairmaonts had those axles and 14 wheels with discs on the front, but theyre pretty hard to find, so an easier solution is to change the whole car to 5 stud wheels, use a xw-xy front spindle and dics brakes, get the tie rod adapters, use a xy rear axle say 2.92:1 and cut to axle housing so its uses two short axles which will bring the track to near XP width.
There are a few catches with this but not big ones, get back and we can talk more about them.
A7M
 
sorry to drag up an old post with this one, but a Chrysler Centura diff will be the ticket, 3.01:1 or 3.08:1 ratio I think (its been over 10 years since I did it) and just about perfect axle length for the XP shell.

It was a straight bolt up pretty much, as the Centuras used a Borg Warner 78.

Hope this is of some help
 
That's where I'd disagree with you. :wink:

Centura diffs are all ten years more worn now, rarer and dearer. These days I'd (personally) pick up an E-series wagon diff - 3.25, LSD, 5 studs, discs - get it narrowed and the axles resplined.

The Centura diff I had, was bent (as I found out later), had a 2.92 ratio and an open centre. After all was said and done the diff people pointed out how I could've started with a more suitable candidate and saved money.

One thing's for sure - buy the spring pads overseas! They are about four times the price when sold here. :x
 
Personally i wouldnt go anywhere near re-splined axles, there original splines are rolled whereas the new ones will be cut on a mill and be soft and not as strong (gain structure flow) so if you can find one that works use that.
I also used compact fairlane diff housings with XT gt or fairlane centres. this is a 8inch diff (miniture 9 inch) and has 28 spline axles, they come with 10 drumm brakes as well.
Another alternative Ive heard of but littel about in Hilux diffs, plenty tough and lotsa ratios.
A7M
 
I'd have sworn the BW axles use machined splines; they appear to have little corrugations along the run. I know they were (are?) topically heat-treated - a mate once pointed out the residual colouring to me just south of the splining.
 
Why not change the gearbox to a Toyota 5 Speed :?:

The motor will not rev so hard in 5th. Keep the diff if it is OK.
 
Why not change the gearbox to a Toyota 5 Speed
Not a bad move, but not the easiest mod in the world to do. I will say though that once you have put it in, you will love the gearbox forever after. The shift quality has to be one of the best around, certainly better that what Ford could offer up. The main problems that I have found with that include the high level of fabrication required to get it to work(crossmember, tailshaft, floor cutting in my case, clutch actuation system, speedo cable) and the fact that there is about a 99% chance that the speedo will not read accurately afterwards. To fix this requires either a custom speedo cable reduction drive box or a conversion to an electronic speedo. It sounds all doom and gloom, but I think there is a company around called Dellow Automotive that you can buy parts through to make the job easier.
 
Back
Top