Indiana BMV title page says http://www.in.gov/bmv/2364.htm
The certificate of title must be applied for within 45 days after the vehicle is purchased or otherwise acquired. If the certificate of title is applied for after the 45 days have passed, an administrative penalty will be charged.
If you are buying a vehicle, ensure that the seller has completed in their entirety both the seller and purchaser sections on the certificate of title before visiting a license branch to apply for a new certificate of title. The seller should remove the license plate from the vehicle at the time of the transaction. The purchaser is responsible for obtaining a new certificate of title, registration, and license plate.
So I would assume if he requests a title from them as required by law - and as I read it he should have done so back in the day up to 45 days after he purchased it, regardless of it being used for racing only as the vehicle is not considered an exempt vehicle due to it being a vin issued vehicle, not a custom specialized piece of machinery, or an off road vehicle by their definitions. They will issue an updated title in his name. He may need to present his bill of sale and the death certificate, but that is not your problem or issue. It is his if he ever intends to sell the vehicle. In any event he should call the BMV to get the particulars in his case.
Once he has legal title to the vehicle in his name he can then sign the title as seller and you can take legal ownership paying the associated fees. Looks very straight forward and as already said they will most likely not give a hoot as long as he is paying the title fees and administration fines for being over 45 days. Money talks.