In HO scale, the X38 box car is available as a resin kit from Funaro & Camerlengo. In addition to the decals in the kits, Mount Vernon Shops offers decals for the series. .

Additional References:

Fischer, Ian, "PRR Class X37 and X38 Box Cars", The Keystone, published by the Pennsylvania Railroad Technical & Historical Society, volume 14 number 4, Winter 1981.

Types of Trucks Used:

Eric Thur comments that from a modeling perspective for X38 trucks, there is little difference between the Young 2D-F21, Barrett Whitehead 2D-F22 and Bowser's PRR 2D-F8. the ASF A4 Ride Control are the only ones available in HO scale, but were only on 100 cars 73700-73799.

Cars on the PRR Roster (as listed in the Official Railway Equipment Register (ORER)):

The X38

From prr.railfan.net OR from BV588 documents, located in collection MG-286, Pa. State Archives, by way of Eric Thur and Joe Acri.

• 50'-6" riveted steel boxcar
• 5/5 dreadnaught end
• AAR shaped side sills
• Double doors with 14'6" opening - (7' & 7'6")
• Equipped with racks for auto parts

Funaro & Camerlengo X38 50' Automobile Boxcar with Panel Roof, Wood Roofwalk (#8460)

Funaro & Camerlengo X38 50' Automobile Boxcar with Recessed Roof, Wood Roofwalk (#8461)

The X38A

From prr.railfan.net...

• 50'-6" riveted steel boxcar
• 300 (76100 to 76399) built by the PRR in 1940-1941
• 300 (57800 to 58099) built by the PRR in mid 1944
• First batch with corrugated roof; second batch with X29-style roof
• First batch had corrugated doors; later order had paneled doors
• End door
• Metal roofwalk
• Some were equipped with veneer flooring for felt loading

The X38B

From prr.railfan.net...

• 50'-6" single-sheath composite boxcar
• Single car (119991) built by the PRR in April 1942
• 11-panel Pratt truss sides
• Single centered 8' composite door
• 5/5 Dreadnaught ends
• Wood roof replaced by Murphy roof after one or two years

The X38C

From prr.railfan.net...

• 50'-6" riveted steel boxcar
• Rebuilt, PRR, 1955, from 58100 to 58299 and 73700 to 75399 series
• Road numbers remained the same
• Rectangular panel roof
• Metal roofwalk
• Single centered 7' door

The X38D

Cars (350) rebuilt from X38 with full-length side sills and renumbered 605000 to 605349. Loading devices were applied to these cars.

The X38F

Rebuilds commenced in 1964:

• Numbered 45500 to 45672
• Rebuilt from X38 73700 to 76099 series
• New side sills and underframe cushioning devices

The X38H

Rebuilds commenced in 1964:

• Numbered 46993 to 46999
• Rebuilt from X38A
• New side sills and underframe cushioning devices
• End doors welded shut

The X38K

Rebuilds commenced in 1964:

• Numbered 45673 to 45950 (shared range with X38L)
• Rebuilt from X38 58100 to 58299 series
  
• New side sills and underframe cushioning devices
• 10' wide sliding flush doors
• New diagonal panel corrugated roof
• Equipped with Evans Side Fillers

The X38L

Rebuilds commenced in 1964:

• Numbered 45673 to 45950 (shared range with X38K)
• Rebuilt from X38 7370000 to 76099 series
  
• New side sills and underframe cushioning devices
• 10' wide sliding flush doors
• Retained original rectangular panel corrugated roof
• Some equipped with Equipco 2D Side Fillers; others with Evans Side Fillers

The X38N

Rebuilds commenced in 1960's:

• Rebuild from X37C 74301
• Converted for pulpwood service
• Door openings sealed with roofwalk sections
• No roof