MPX stands for Manske-Puckett Experimental. The MPX Special was raced as an H Modified car at SCCA races in Southern California, circa 1960. It was powered by a Crosley engine.
"Walt Manske was a former record holder in model airplane speed contests who decided to go car racing.
He built the entire car by himself including pounding out the nifty aluminum body on sand bags. Joe Puckett, who had been racing a Triumph TR-3, bought the car and immediately proved to be as fast as Walt and then went on from there,"1 reports Curt Anderson.
"It should also be noted that this car was unique in that Walt (Manske) had the engine laid over on its' side by some 30 to 45 degrees (don't know the exact amount). As far as I know this is the only Crosley powered car to incorporate this feature."1
Curt also says that, the bottom color "picture of Joe Puckett's car is deja vu for me as I was his go'fer off and on from 1959 thru 1961. It could be that Frank Davis was the driver in that particular shot since Joe always wore a black driving suit and a black helmet."1
"Puckett was a long-time "H" Modified enthusiast & wrote frequently on the subject in vintage racing magazines."2
Joe also authored the book on H Modified racing entitled Big Drivers in Little Cars. The book has been out of print for some time now, but there was talk of a possible second publishing.