Thread: V8 to isuzu

Originally Posted by Lotz-A-Landies

Isn't the V8 County T/F hi ratio 1.41:1 waaayyyy tooooo low for the 4BD1.

Where did that come from? Tdi defenders run that, no county's I know off

Originally Posted by Bearman

Your 85 County should have an LT95 4 speed already in it ( same as the Stage 1 only different transfer hi gear ratio). Use the better one of the 2 and change the intermediate shaft hi range ratio. The gears you need are FRC4500 and FRC4032, 45/26 teeth. This will give you the 0.996 ratio that you need for the Isuzu. The Stage 1 box will also have a longer front transfer output housing and shaft and a DC shorter front driveshaft. For these reasons I would be using the County box if it is still OK- just put the Isuzu clutch bellhousing and longer clutch pushrod and throwout bearing from the Stage 1 box onto it. You will probably have to reshim the intermediate shaft anyhow. Drop the transfer sump on your Stage 1 and check what ratio is in it (do a tooth count) as it could already be changed to 0.996. The Stage 1 will have the small fat handbrake assembly whereas the County will have the larger better handbrake on it, but if you want to change the County one onto the Stage 1 box you will also need to change the output housing that the larger one is fitted on. Everthing is bolt up achievable if you have a bit of mechanical knowhow. As said above you will need the Isuzu engine mounts welded to the chassis in lieu of the V8 ones which are very different. The radiator is another story as the Stage one radiator mounts are different to the County. You can modify the County V8 one by swapping the inlet/outlet pipes on the tanks if the core is still OK. The PS is also another task also as some Stage 1 motors did not have provision on the timing cover for a bolt on PS pump. Do a search on here and you will have many hours reading on this conversion but it is all doable if you have the patience and mechanical skill. The only difference between an Isuzu army perentie box and a civvy Isuzu box is the more durable tapered roller intermediate shaft assembly in the transfer case instead of the standard shimmed roller bearing assembly. The gearbox and everything else in the transfer case is the same.

CORRECTION!!!!
Just realised that I misprinted the hi gear part number It is FRC4050 NOT FRC4500. My apologies if this has caused any dramas.