This is a pair of original GM 3748770 cylinder heads. To my knowledge, the 3748770 heads were reserved for 1958 Corvette applications only. These heads have casting dates of B 4 8 and B 11 8 as shown. These dates decode as February 4th and 11th, 1958. These are also known as 58X or X58 heads do to the external cast “X 58″ below the exhaust ports. These are very hard to find factory 1958 high performance heads. These heads are in good condition overall. Both heads recently has the valves and springs removed and were cleaned and magnafluxed for cracks by Santa Cruz Auto Parts in Santa Cruz, CA. Both heads were found to be free of cracks and are good rebuildable cores. The spings, valves, retainers, and locks are included in the sale. Both heads have no porting on the intake or exhaust ports. The combustion chambers are stock with no modifications. All threads are in good condition with no helicoils or thread inserts. The X 58 castings are clean and chrisp as shown. Core may require valves, guides, seat work, and other machining and parts that are common to the building process. Finding an original dated pair “X 58″ heads in this condition is not an easy task. Don’t miss this awesome pair! This is your chance to own the original February 1958 dated 3748770 heads you have been dreaming about at a GREAT PRICE! Don’t Miss Out! Check out my other listings for more rare and hard to find parts. The item “OEM GM 3748770 Cylinder Heads 1958 Corvette 283 Dated Feb 58 No Porting 58 X X58″ is in sale since Thursday, December 16, 2021. This item is in the category “eBay Motors\Parts & Accessories\Car & Truck Parts & Accessories\Engines & Engine Parts\Cylinder Heads”. The seller is “super-novass” and is located in Santa Cruz, California. This item can be shipped worldwide.
- Interchange Part Number: 1957 1958 1959 57 58 59 Chevy Chevrolet
- Vintage Car Part: Yes
- Type: Cylinder Head
- Brand: OEM