Enginetech R37558-040 Cast .040″ Oversize Piston Ring Set for 1955-1981 Chevy Ford Mercury 4.3L-5.6L 265-340ci V8 – Complete Engine Ring Set
Original price was: $55.94.$39.35Current price is: $39.35.
Description
Enginetech R37558-040 is a cast .040″ oversize piston ring set for 1955-1981 Chevy, Ford, Mercury, Jeep 4.3L-5.6L 265-340ci V8 engines, sold as a complete set covering all cylinders.
Important Notes:
- Sized for cylinders bored .040 inch oversize. Verify your finished bore diameter with a precision gauge before ordering – rings sized for the wrong bore will not seal correctly.
- File-fit and gap each ring to the manufacturer’s end-gap specification for your application before installation. Improper end gap causes blow-by or ring-end butting under heat.
- Replace piston rings as a complete set during any rebuild. One set covers all cylinders for the engine.
- Cast. 5/64 5/64 3/16.
| Part Number | R37558-040 |
| Grade | Cast |
| Bore Size | .040″ Oversize |
| Ring Stack (Top/2nd/Oil) | 5/64 / 5/64 / 3/16 |
| Standard Bore Diameter | 3.750 in |
| Quantity | Complete set – covers all 8 cylinders |
| Engine | 4.3L-5.6L 265-340ci V8 |
| Year Range | 1955-1981 |
| Makes | American, Buick, Chevrolet, Ford, Jeep, Mercury, Plymouth, Pontiac |
| Country of Origin | US |
| OEM Cross-Refs | Hastings:568, FEL-PRO:E-240X, Perfect Circle:50618 |
Sold as a complete piston ring set – one set covers all cylinders and is required per engine.
Fitment:
- 1955-1955 Mercury Custom 4.8L 292ci V8
- 1955-1955 Mercury Montclair 4.8L 292ci V8
- 1955-1955 Mercury Monterey 4.8L 292ci V8
- 1955-1955 Pontiac Catalina 4.7L 287ci V8
- 1955-1955 Pontiac Chieftain 4.7L 287ci V8
- 1955-1955 Pontiac Star Chief 4.7L 287ci V8
- 1955-1956 Chevrolet Corvette 4.3L 265ci V8
- 1955-1956 Ford Customline 4.8L 292ci V8
- 1955-1956 Ford Mainline 4.8L 292ci V8
- 1955-1957 Chevrolet Bel Air 4.3L 265ci V8
- 1955-1957 Chevrolet One-Fifty Series 4.3L 265ci V8
- 1955-1957 Chevrolet Sedan Delivery 4.3L 265ci V8
- 1955-1957 Chevrolet Truck 4.3L 265ci V8
- 1955-1957 Chevrolet Two-Ten Series 4.3L 265ci V8
- 1955-1957 Ford Club 4.8L 292ci V8
- 1955-1957 Ford Fairlane 4.8L 292ci V8
- 1955-1957 Ford Skyliner 4.8L 292ci V8
- 1955-1957 Ford Sunliner 4.8L 292ci V8
- 1955-1957 Ford Thunderbird 4.8L 292ci V8
- 1955-1957 Ford Victoria 4.8L 292ci V8
- 1955-1962 Ford Country Sedan 4.8L 292ci V8
- 1955-1962 Ford Country Squire 4.8L 292ci V8
- 1955-1962 Ford Ranch Wagon 4.8L 292ci V8
- 1956-1956 Ford Club 4.8L 292ci V8
- 1956-1956 Ford Customline 4.8L 292ci V8
- 1956-1956 Ford Fairlane 4.8L 292ci V8
- 1956-1956 Ford Mainline 4.8L 292ci V8
- 1956-1956 Ford Park Lane Wagon 4.8L 292ci V8
- 1956-1956 Ford Skyliner 4.8L 292ci V8
- 1956-1956 Ford Sunliner 4.8L 292ci V8
- …and 91 additional applications
Enginetech piston ring sets are manufactured to OEM specifications and offered in both premium and cast grades to match the demands of stock rebuilds and moderate-performance builds. Each set is application-specific, with ring widths and end-gap characteristics matched to the bore and groove geometry of the engine family it serves. Ring sets are sold by bore size – standard for unmachined bores, with oversizes for blocks that have been bored and honed – so verify your finished bore diameter with a precision gauge before ordering, since rings sized for the wrong bore will not seal correctly. Always file-fit and gap each ring to the manufacturer’s specification for your application, and replace rings as a complete set during any rebuild. Enginetech documents every set with the ring stack dimensions, bore size, and cross-references so the correct set reaches the bench the first time.
WARNING: This product can expose you to chemicals including lead and nickel, which are known to the State of California to cause cancer, birth defects, or other reproductive harm.

