I've rebuilt approximately 75 totaled cars over the last 30 years. The laws have changed quite a bit over that time. After repaired; the vehicle must undergo an "Enhanced Safety Inspection" ESI. At first I thought it would be more difficult but it has made the process a lot more straight forward. I did this with my FFR MK2 back in 1999. The dealer where I buy my cars through is an ESI certified garage and licensed PA registration center, so you have a true "one stop shopping". SEE below for current procedures for "Special Constructed Vehicles. All forms are available online.

Specially Constructed Vehicle Titling Procedure
PURPOSE
This Fact Sheet explains the requirements for titling and registering specially constructed vehicles.
DEFINITIONS
Specially Constructed Vehicle - A vehicle not originally constructed under a distinctive name, make, model or type by a generally recognized manufacturer of vehicles.
Some examples of vehicle configurations which would require a specially constructed vehicle title include but are not limited to:
- Vehicles assembled from a kit
- Vehicles assembled from various vehicle makes/model years
- Dune buggies
- Glider kits
- Homemade trailers
PROCEDURE AND DOCUMENTATION REQUIRED
 All specially constructed vehicles must undergo an enhanced vehicle safety inspection to ensure the vehicle is in compliance with all equipment and inspection requirements (even if it would not normally be subject to a periodic safety inspection). This inspection must be performed at an enhanced vehicle safety inspection station. A list of these stations can be found at www.dmv.state.pa.us. Click on the link for Business Partner Info, then Station Owners and Mechanics.
 Once the vehicle has successfully passed the enhanced inspection, the enhanced inspector or certified document reviewer will photograph the vehicle and examine the documentation presented by the vehicle owner to support titling the vehicle. Required documentation includes, but is not limited to:
 Form MV-426B (Application for Reconstructed, Specially Constructed, Collectible, Modified, Flood, Recovered Theft Vehicles and Street Rods) with all applicable signatures. Note: Obsolete versions of Form MV-426 or MV-426B with a revision date prior to December 2006 (12-06) will not be accepted.
 Proof of ownership in the form of:
o Pennsylvania Certificate of Title or Salvage
o Certificate of Title or Salvage issued by another state or jurisdiction
o Manufacturer's Statement of Origin or Certificate of Origin (MSO/MCO)
o Bill of Sale
o The following documents are not accepted by Pennsylvania as proof of ownership:
- Form 907A issued by the state of New York
Any title, certificate of origin, statement of origin or certificate of salvage that indicates the vehicle is to be used for parts only; is not suitable to be rebuilt or titled; or is not designed, constructed or intended for use on public roadways.
 Form MV-1 (Application for Certificate of Title) if the applicant's name does not appear on the face of the certificate of title or salvage
 A detailed description of how the vehicle was configured and assembled
 Proof of Insurance (except Specially Constructed trailers)
All applications for a Specially Constructed Vehicle MUST be submitted to the Department for review and processing. Specially constructed vehicle applications cannot be processed by on-line business partners. Any application submitted for a specially constructed vehicle title may be delayed should it warrant further review by PennDOT and/or the Pennsylvania State Police.
PENNSYLVANIA INSPECTION REQUIREMENTS
After the vehicle is titled and registered, Specially Constructed Vehicles (except trailers having a registered gross weight of 3,000 pounds or less) are subject to periodic safety inspections. Periodic inspections can be performed at any inspection station throughout Pennsylvania. A vehicle is only required to be inspected at an enhanced vehicle safety inspection station for initial titling.

All specially constructed vehicles are assigned a year of "00" and didn't require an emissions test. (not sure if that is still the case but the inspector said that was what let the computer bypass the emissions when registering)