First, hello. First time posting. I have looked and looked and even searched your site and am quite surprised no one posted about a solid axle swap on a GMT400. Now, I have the idea I want and the parts gathered to begin. Now....Before I continue, I ask to please curb criticism about the direction I want to go and the parts I am using. Based on what I have read in your forums, that does look like its kept to a minimum.
About the rig. Its a 1988 C1500. The history to this truck is in depth and extensive and not really relevant to the build. I will not be doing anything with the 5.7L engine. It was built about 5 years ago. Mated behind the 5.7L will be a GM variant NV4500. Behind that will be a fixed yolk Borg Warner 44-70 transfer case. Drive shafts will be made once the truck is sittiing on the axles. The axles will be the 1999 era Superduty Dana 60 with the 36.5 spring pad spacing. The rear will be the matched axle AAM 10.25. These axles were chosen due to the large availability of parts and the ease of replacement. I am not gonna run extremely large tires so the issues with the wide perches are moot. The tires will be 35x12.50x17. Since I am running a 33x12.50x15 on it now with minimal rubbing issues....with the truck lifted....I wont have any at all.
About me....I am an extremely capable tech already. My fab skills are good, but not the best. But I can fab things to last. So if something is technical, speak it. I get it.
So....First question....pretty basic....What hydroboost and master cylinder combo would be ideal for a dual piston caliper setup on all 4 wheels? I rather not run a vac brake booster. These trucks brakes were always iffy on the best of days. I want to have better than great stopping power.
Second question.....I am not running a crossover steering set up. Again....great if youre hard core off roading....I am not. Ford uses an inverted T set up that works on their trucks and goes UNDER the leafs. Ford uses an inside frame steering gear box GMT400s do as well. The difference is the pitman arm. GM it points back towards the engine. Simply turning the GM pitman 180* would cause reverse steering. Ford it points foward toward the radiator. I could probably make the GM gearbox work.....But I am thinking a Ford steering box would be the way to go since it points out far enough to clear the leafs. What Ford steering gear box would bolt up? What box would require minimal modifications?
Third question.....What source would you use for aftermarket drop pitman arms?
Fourth Question.....The rear shackle bracket on the front leaf springs on the Superduties are inside the C channel of the frame. Like I said....I am going this route....If I need more lift to clear, I can always get the shackle extenders and get the height I need. I digress....On the Superduty, like the GMT400s, the frame goes open C channel to the rear of the vehicle. Ford solved the issue by adding a section of frame inside the channel to add rigidity. Since the leafs I am using dont go as far back to the fully opened C channel, its still inside the "boxed" portion of the frame. Do you think this part of the frame is strong enough to accommodate the rear shackle without reinforcement? A sub question to this, With the springs in the unloaded position, which way would I mount the shackle so when its loaded, there wont be any issues. I read that the proper end position would be about 25 degrees front or back depending if I want a stiffer or softer ride. Since I will be drilling a 2" hole in the frame, I would like to measure a million times and cut only once. So placement....paramount.
Fifth Question.......I am no fan of alloy rims. Especially where I live, vehicles will get stolen with Pepboy rims if they look nice enough. I like the durability of steelies. What Ford steelie offers that GM rally wheel look in a 17" rim? 17 is the choice as there are more options for tires. 16 is pretty slim and expensive from what I was looking at. Overall tire size goal is 35x12.5x17. Since 33x12.5x15 work on my 2WD truck now with minimal issues....the extra height will be no big deal once all said and done and with the gearing, transmission I have sorted out.....will give me a similar RPM and power band expectation. I know fuel mileage will be worse....But if I was worried about gas mileage, I would drive a Prius. Besides.....I paid $4 a gallon before for that beast. 36 gallon tank......C note every fill up.....you get the idea.
I know this is ALOT from a noob to the site. This project has been in the phases of getting done for the last 7 years. I have owned the truck for 15. This truck is not gonna get replaced anytime soon. So I would like to thank each and every one of you who offer your help.
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