Chevy 350 or Ford 351?

Which engine is more reliable?
Which engine has the better horsepower potential?
Any help is appreciated

Which Chevy 350? L46, LT1, L82?
Which Ford 351? Windsor, Cleveland, or Michigan?

The most HP potential probably comes from the 'Racing Boss 351', a crate engine from Ford Racing Performance Parts. The block was based on the 351 cu in Windsor engine, but the finish build results displacement of 454.38 cubic inches

The Chevrolet/GM Turbo-Fire 350, introduced 1967, splits the difference between the older two 351 Fords statistically. The 351 Windsor, a tall-deck small-block developed from the 221/260/289/302 for the 1969 model year, had main-bearing issues during preproduction testing but Ford considered the final result good for 100,000 miles between overhauls. The 351 Cleveland, a particularly robust small-block implementing many of the lessons learned on the 429 and 460 Lima, was introduced 1969, the same year all Turbo-Fire V8's went to the large crank and rod bearings introduced on the 350, and held up better in severe service. The 351 MAC engines developed for Ford F- and E-Series trucks had serious issues with block cracking in 1977-78 due to a design flaw in the sand cores; this was remedied for 1979-82.

As delivered, the 351 Cleveland has the best breathing of all the V8's listed above.

It's irrelevant. Nothing you can afford to build with either engine will outrun my Tesla Model 3 in a quarter mile. While you'll spend 5 bucks on gas every time you struggle to do a quarter mile in 13 seconds I'll do it in 11 and it won't cost more than 10 cents in electricity.

There are MILLIONS of BOTH of these engines out there. They are equally reliable, IF they are properly serviced and maintained.