[BrianPaul]

The mighty 391 truck blocks designated with a numbering sequence like D3TE, D4TE, etc. denotes that it is an FT engine and the number is the year it was produced. I made one into a 428. These engines were made to be rebuilt many times and therefore have very thick cylinder walls. Get yours sonic checked and see what you can do. Mine took an 0.080 over bore, to 4.13", with plenty left to spare.