Since I don't want to hijack the other post I start a new one.
I see you run the radiator in the back, how do get the airflow in there ?
I thought about moving the radiator in the back also, but I don't want to hack up a perfectly good and very rare body. I also want to keep the possibility tp store some equipment and 2 spare tire as we plan to also do some desert marathon races with the Patrol.
I do have a lot of space in the front to push the radiator about 15-20cm back from the original position since we use the V6 Chevy and that is a very compact and lightweight package. Saves us about 180kg of weight above the front axle compared to the stock 4.2 Diesel.

The radiator on the back is just for the intercooler and the transmision coolers. I have a VH45 with a Garret T04z on it and a PWR 6x10 water to air intercooler. I also have fitted a light alloy motor except I went a bit overboard on the HP.
Under the bonnet I still have tripple row TD42 radiator which manages to keep in cool but I haven't down any long distance high speed races yet, only winch challenges. Over Xmas we plan to get it into the sand and test the cooling and high speed stability.
I've also pushed the rear axle back 265mm to get a MWB (104") chassis. The increased stability is great and combined with twin shocks etc it really handles well now.
I have also shifted the body back 75mm on the chassis which is needed to clear the firewall for the V8. All told I now have about 50:50 weight distrubution and it is about 2000kg in full race trim. ie recovery gear, spares etc. The engine I used is 130kgs lighter than th TD42 and it has the same torque at 2000 rpm yet has peak torque at 4000 rpm and then we turboed in onto top of that! It also uses the Patrol auto as factory so bolted in. (sort of!)
As for hacking the body up! Harden up I say! :flipoff2: I had no choice cutting mine down as the rear body mounts all got torn out! From the truck I started with I still have the drivers side guard, the main body shell, bonnet,some of the auto, the front drive shaft and part of the steering colum. The rest ie chassis, axles, doors, dash, engine T-case etc has all been either bent, broken or worn out!

Hacking up the body, well sort of. The wheel wells are already redone to accomondate 35's with minor lift and still clear them at full bump. I bet running 37's some day shouldn't be a problem. I want to keep the wheelbase as is for keeping it street legal which is mandatory for most events here.
My engine/tranny combo is about 230kg less than the factory TD42 with heaps of avail. space in the front. The engine ends about where the stock battery mount starts at the front. I could mount the radiator further back to get away from mud sticking in it. I don't run any turbo, so the only other stuff I have to stick in there is the engine and tranny oil cooler.
My goal is also to be below 2000kg race ready. I guess it'll be a sporty ride with the 4.3 Chevy and the 4.63's out of the RD28T GQ:D

I'm trying to get some 4.6's at to lower my gearing a bit. Having a 7000rpm redline when the gearing is designed for 4200rpm does make for a fair bit of speed! ie about 160kph in low range!
The front 2 cylinders are above the front diff so a lot better than factory but not as good as yours! The biggest problem is the VH45 is a similar external size to a big block Chev. The joys of Quad cams! However it is worth the effort to have a lighter truck with over 5 times factory wheel HP!
I have factory auto and that is a lot lighter than 5 speed but I'm not sure how much? Also batteries are at the back so front axle load is over 200kgs lighter.
My truck is completely street legal in race trim. It has had independant engineering certs but that is a relatively easy process in NZ and costs about $400.
I'm thinking about 37's but it means getting a tyre like a Simex that is bigger. The 36x12.5 Simex with triple centre blocks isn't very good down here and not many use them. I've been looking at Maxxis Trepador competition but aren't convinced that they are the option. We have the situation where a taller tyre may not perform better due to the poorer tread design? The joys of doing races that require all round ability!

I'm in the same boat as you with the tyres, thought about the classic MT117 already. They measure about 36".
I do run 4,63's out of a RD28T GQ with the rear disc brakes and factory rear locker already. The VH45 would be nice, but wasn't avail. in Europe so finding one is close to impossible. I might move on to a LS1 someday if I get one for a good deal.

I ran the MT117 Extreme for a season and they were very good if you had a firm wet surface but if it was soft then they dug way to fast to be a good all round tyre! Unbeatable it certain conditions but to extreme in general. It is amazing the difference between them and a Simex when they look so similar, until they are along side each other that is!

I know, but I wasn't talking about the Extreme, I meant the classic MT117 in 280/85.
For me, there's no such thing like a perfect all around tyre. It all depends on the type of event and terrain.

Cool. It is amazing the number of people who thing the Silverstone is an exact compy of the Simex!