[52wrench]

Hi - First time poster here. I'm doing a Cummins 4BT swap into a 1990 F150 extended cab 4x4. This will be pretty much a highway queen, no serious off- road. I'm going to run 305/85/16 Denman Coyotes to get the overall gearing I want. Its getting a '79 D44 front along with 9" rear. I'm planning on using 4" TTB coils and the stock TTB buckets along with a 1" body lift. I need the body lift for clearance for the downpipe for the high mount turbo or take a hammer and torch to the firewall. Can someone recommend what coils to get? The 4BT weighs approx 225 lb more than the 5.0 that came out. I don't need a lot of flex for this duty but I want something heavier than the stock. I was browsing someone's catalog tonight and saw some 4" coils for the 1984 150 with the big block, do you think those would work? I'll be using the stock '79 arms. Will the 4"+1" work ok with the narrow 36's for the pavement? Thanks.

 

[masterbeavis]

the 460 weighs 720# full motor dry, 640 bare, with no intake or carb. 5.0 is 460#, 351W 525/545# depending on who you ask. Use the 460 springs and call it a day. Otherwise, call the various lift kit/spring manufacturers with your specifications, see what they recommend.

As far as tires are concerned, you can barely squeeze 33's without rubbing, so if you do a 5" lift, I think you might be OK with what you have. If not, you can trim away whatever sheetmetal is in the way. Do a search for trimming fenders, you can do it cleanly without butchering your truck. It is a common mod here to cut fenders to fit larger tires, instead of lifting a rig.

 

[icb12]

From the Cummins Shop Manual
Section E- Engine Identification
Page E-5
Engine weight
Dry, less flywheel and electrical components

4B3.9, 679 pounds 4BT3.9, 705 pounds 4BTA3.9, 725 pounds


go with the big block springs..

also check out
http://www.4btswaps.com/forum/index.php

how hard are you on the skinny peddle?? d44 may not do the trick.., though if its mostly a highway deal.. then your probably good..

 

[52wrench]

Thanks guys. Turns out its actually the 6.9L diesel that they put in the 150 in 1984 only, that's news to me. I suspect that's a little heavier than the big block gasser, I'll have to find a weight spec for it. I think that's the spring I'll start with. Its a Rancho spring. I was going to go with a Detroit locker in the front and Truetrac in the rear but now I think Truetracs frt and rear is the way to go for a pavement queen.