S1 monty ghia, 3.9 LSD

[kratas]

Hey guys, was just hoping for some feed back here. Took the car down to my mechanic because I noted that when changing from neutral to drive or reverse, there is a distinct lag, before a clunking engagement. Thought that the diff might need a service (notorious on the AU) so asked the bloke to check her out.

He said it was definatley a slack diff, and that it would need to be fitted with a recoed one. Gave me the number of a diff place about 20ks away from his shop, saying that he knows that the guys dont rip you off and do a decent job etc.

Onto my question. I have been toying with the idea recently of changing the diff anyway, so I figure while they are putting in the labour, I might as well change the diff ratio and also put LSD on the bad boy.

Its a series 1 fairmont ghia. 3.1 diff ratio (iirc) single pegger. With IRS. I was wondering, should I just get a swap to an XR6 LSD diff, and have the ratio changed to a 3.9. I am sick to death of the 0-50kmh 15 second foot to the floor, titanic geting out of harbour feel of the fairmont ghias long diff ratio, 4 speed slug box and damned ECU.

So, I was thinking 3.9 LSD and a 3 grand stallie. What is your opinions? will a straight swap be possible? is the ratio good? one mate said 3.9 is too short, and I should go 3.7 and another said I should go 4.11.... lol

thanks in advance