Did a google on this topic and found something referring to a Ford frame, but you might want to read it.

FRAME—RIVET REPLACEMENT WITH BOLTS— Article No.
SERVICE TIPS 97-4-7

FORD: 1980-1996 BRONCO 1980-1997 ECONOLINE, F-150-350 SERIES
1983-1997 RANGER 1984-1990 BRONCO II 1986-1997 AEROSTAR 1988-1997 F SUPER DUTY, F-47 1991-1997 EXPLORER
This TSB article is being republished in its entirety to include 1997 model year vehicles.
ISSUE
Damaged or loose frame rivets should be replaced with approved service bolts. WELDING IS NOT ACCEPTABLE.

ACTION
If service is required, replace standard rivets with approved service bolts. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
NOTE THE “HUCK” RIVET BETWEEN THE #1 CROSSMEMBER AND THE LH FRAME RAIL SHOULD BE SERVICED PER TSB 91-25-18. THIS PROCEDURE DOES NOT APPLY.
1.
Inspect for a loose or damaged rivet.

2.
Remove any damaged or loose rivets.

a.
Drill a 3.175mm (1/8••) hole through the rivet.

b.
Redrill the same hole through the shank of the rivet.

•
Use an 8.731mm (11/32••) drill for 3/8•• and 10mm rivets.

•
Use a 9.525mm (3/8••) drill for 11.113mm (7/16••) rivets.



c.
Remove the rivet head with an air chisel.




d. Drive out the rivet with a punch and hammer.
3.
Line ream the hole to the replacement bolt nominal size with a hole tolerance of ±0.127mm (0.005••).

4.
Free hole of burrs after reaming to allow bolt head and nut to seat properly.

5.
Select the bolt length to have a minimum of two (2) threads protruding from outer face of nut. Refer to the following Bolt Selection Chart for correct parts usage.


NOTE IF A FLANGE HEAD NUT AND BOLT ARE NOT AVAILABLE, GRADE 5 HEX HEADS MAY BE SUBSTITUTED WITH ONE (1) FLATWASHER REQUIRED UNDER THE NUT AND ONE (1) FLATWASHER REQUIRED UNDER THE BOLT HEAD.
6.
Check to be sure there is a 12.7mm (1/2••) minimum clearance of bolt to adjacent components, except engine and transmission, which must have at least 19.05mm (3/4••) clearance to allow for powertrain roll.

7.
Tighten the bolts to the specifications shown in the Bolt Selection Chart.


NOTE GRADE 8 BOLTS MAY BE SUBSTITUTED FOR ANY APPLICATION.
PAGE 1

Article No. 97-4-7 Cont’d.
BOLT SELECTION CHART
Rivet Diameter Bolt Size Bolt Part Number Washer Part Number Nut Part Number Torque Specifications
3/8•• and 10mm 7/16•• 7/16••-14x1.25•• 7/16••-14x1.75•• 1/2••-13x1.5•• (Grade 5) 1/2••-13x2.0•• (Grade 8) 56561-S2 56563-S2 56783-S100 383896-S2 Not Required Not Required Not Required 44879-S2 382400-S2 382400-S2 33773-S2 33773-S2 45-68 N•m (33-50 lb-ft) 45-68 N•m (33-50 lb-ft) 72-102 N•m (53-75 lb-ft) 102-142 N•m (75-105 lb-ft)

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1948 Chevy 2-Ton