This Bullneck frame has a 30 degree rake. Its also called a Knucklehead frame was mfg from mid 1946 to mid 1947. Check out the neck design and top motor mount design and it is a straight leg design.
This Wishbone frame has a 30 degree rake. Its also called a Panhead frame was mfg from 1948 thru late 1954. Check out the locking neck design and top motor mount design and its front legs are of the wishbone design also know as a Bow leg frame.
This is a Straight leg frame has a 30 degree rake. Its also called a Late Panhead frame and can be use with a Shovelhead engine was mfg from late 1954 - 57. Check out the top motor mount design. Also all the frames were brazed together except the 1957 which was welded together.There is an old saying that goes you can put a panhead motor in a Knucklehead frame but you can't put a Knucklehead motor in a Panhead frame.
Here is a close up view of the Bullneck. The Bullneck has a 30 degree rake from mid 1946 to mid 1947 (VC-32).
Here ia a close view of the locking neck it aslo has a 30 degree rake from mid 1948 thru 68 (VC-1).
These sleeving joints are found on the 1937 thru 1947 models (VC-100) talk about adding detail to your skooter on the rear fender brace VC-41.
The transmission outrigger support (5th mount) is on all the models from 1936 thru 1969 (VC-60).
The seat post cluster (yoke) fits on all the models from 1952 thru 1957 (XE-1B).
These sidecar loops (lugs) fit the Straight leg design frames from 1937 thru 47 and 1954 thru 1957 they have hallmarks with YE-761E / YE-762E (VC-5L left side / VC-5R right side)
The front motor mount that I use are the 1953 thru 1957 with casting number 47664-48Y (VC-29).
This rear motor mount / front transmission mount are found on the 1958 and up models with casting number 47641-68Y (VC-5).
The rear axle carriers (plates) are on all the models from 1936 thru 1957 with hall marks XE7 / XE6 (VC-108R / VC-108L).
EARLY FRISCO STYLE CHOPPERS ...(these were also called Barbary Coast chopper, Nor Cal chopper, Ghetto Blaster or true Outlaw skooter). FRISCO style frames consist of the following, a window neck (spyglass) with a 30 degree neck, sidecar loops cut off and filled (bones), remove the foward control tabs off the front motor mount (optional) if your running mid controls, remove the running board lugs, add mid kick stand tab added to take the Sportster kick stand, add rear master cylinder mounting plate (optional) add a anchor for disc brake set up ... then add a Sportster tank early or a late style of your choice and put your rear fender at 1 o'clock rigid mounted ... now you have the AGGRESSIVE TRADITIONAL SLIM LOOK.