But alas, it's a 3408 already in the KW wrecker kit. I'll see what other truck models I have laying around that might have it.
Found this on a forum. Its a list of engines in kits.
Caterpillar 1160
AMT Ford LNT-8000
Caterpillar 3406A
Revell/Monogram Snap Kenworth W 900 Aerodyne
Revell/Monogram Snap Peterbilt 359
Caterpillar 3408
Revell AG Kenworth W 900 VIT
Revell AG Kenworth T 900 Australia
Revell AG Kenworth W 900 Dump Truck
Revell AG Kenworth W 900 Wrecker
Cummins V903
Ertl International Transtar F-4270
Cummins NHC-250
AMT White Freightliner Dual Drive
AMT White Freightliner Single Drive
AMT/ERTL Autocar 9964B Dumptruck
AMT Autocar A64B
Cummins NTA-370
AMT Kenworth K 123/125
AMT Kenworth W 900 Alaskan Hauler
AMT Kenworth W 925 Challenge Transit Mixer
AMT Kenworth W 923/925
AMT Kenworth T 600A/Canepa
Cummins NTC-350
AMT White Road Boss (Road Boss box says NTD-350 but I don't know of any such engine so it must be a NTC-350)
AMT Peterbilt 359 1100 Cab Wrecker (T533 and all issues after that)
AMT Peterbilt 359 1100 Cab (T501 and all issues after that)
AMT Diamond Reo
AMT White Western Star
Cummins NTC-400
Italeri Freightliner FLC
Revell AG Mack Superliner
Revell AG Ford LTL 9000 (no aftercooler)
Revell AG Ford Aeromax (no aftercooler)
Italeri Freightliner FLC Dumptruck
Italeri Western Star
Italeri Mack Superliner
Italeri Freightliner FLD (no aftercooler)
Cummins NTC-475 (twin turbos)
Revell AG Peterbilt 353
Revell AG Peterbilt 359
Revell AG Peterbilt 359 Bill Signs Trucking Conventional
Revell AG Peterbilt 359 Wrecker Stepp's Can-Do and the new Revell US re-issue
Revell AG Kenworth K 100 Heavy Hauler Tri-drive
Revell AG Kenworth K 100 VIT Australia
Revell AG Kenworth K 100 Aerodyne
Revell AG Kenworth T 600A
Detroit Diesel 8V-71
AMT Peterbilt 352 Pacemaker COE (T551 and all issues after that)
AMT Peterbilt 359 California Hauler "Small Window" Unilite Cab (T500-500, T500 and the newly reissued AMT 866)
AMT Peterbilt 359 "Small Window" Unilite Cab Wrecker (T522)
AMT GMC Astro 95
AMT Chevrolet Titan 90
AMT American LaFrance
Ertl International CO-4070A
Ertl International Transtar II Eagle
Detroit Diesel 8V-92T
AMT Kenworth K100 Aerodyne
AMT/Matchbox Kenworth K100 Aerodyne Papa Truck
AMT/Matchbox Kenworth K100 Aerodyne Hideout Truck
Detroit Diesel 8V-92
AMT/Ertl GMC General
AMT/Ertl Chevy Bison
Detroit Diesel 12V-71T
AMT Kenworth W900 Super Boss (Termo King)
AMT/Matchbox Kenworth W900 Super Boss (Bandag)
AMT/Matchbox Kenworth W900 Bandag Bandit
Detroit Diesel 16V-71
AMT/Ertl International Payhauler 350
Detroit Diesel Series 60
Italeri Peterbilt 377AE
Italeri Peterbilt 378
Revell AG Peterbilt 377AE
International V-800
AMT/Ertl International Paystar 5000
AMT/Ertl International Transtar 4300
Ertl International F-2674/2575
International Maxxforce 15
Moebius International Lonestar
Moebius International Pro Star II
Mack ENDT-673
MPC/AMT/Ertl Mack DM600
Mack ENDT-865
MPC/AMT/Ertl Mack DM800
Mack ENDT-675
AMT/Ertl R-685ST/R Model
Mack ENDT-676 Tip Turbine
AMT/Matchbox Mack Cruiseliner COE
Turbine Experimental
AMT GMC Astro 95 (T510 from 1971-72)
I have some of these kits that have Detroit Diesel engines in them if that's what you're looking for, if they are the right version.