It's no wonder the Slant 6 is so great!

RGAZ said

To answer the OP question with rumor only....

There is a post somewhere that the block was over-designed and used excessive thickness and webbing due to the possibility it was going to be an aluminum block. Don't know if its fact, but the block itself is quite a beast.

The unequal runner length of the manifold is helpful for wide range fuel of operating conditions (short runners and long runners) so there is some advantage for even cylinder balance (even though fuel equality is not the same). Some life advantage there.

Combustion chamber flow is basically a u-turn, very bad for higher rpm power but great for regular driving use which gives the durability.

Lastly, no one expects it to be sporty and therefore is driven as such.

Just my 2 cents or less.

RGAZ

Click to expand...

1) The aluminum block thing is total wives-tale bullsh*t, still propagated by the Uncle Tonys of the world. Two completely separate, different, & dedicated castings... Member slant six just aquired both an al. 225, & the 1st al. 170 I've ever seen pics of.
2) The 'crossflow over reverse flow' is also bullsh*t, the only bad thing about the system is the exhaust heating the intake in performance apps, & high temp regions stock.
3) At the time, the commitment to the individual runner design(while far from perfect) was a big advantage over every other economy six, & was better than GM's new boxer 6 in the Corvair...
It's hilarious how folks are compelled to chime in with why something sucks, when positive comments are solicited, the Slanty was far & away the best of all the 170ci sixes of the day....when it was a BIG deal.