You guys might be surprised at how much torture you can putt
You guys might be surprised at how much torture you can put that old factory GM 454 or 427 block through. It is tough as a Rhino Hide.
Merlin II block was supposed to be a stronger aftermarket replacement for the Factory GM BowTie. At least it was when I ordered one.
Almost a year later when it was finally finished according to Merlin it would only accept the factory advertised max bore of 4.600 in extreme examples but would be ok at a 4.560 bore. Likewise according the Merlin (World Products) It might or might not be able to clear the 4 3/4 crank with grinding. What really made me mad was that at the time according to them that block should handle 900 to 1,000 hp.
I had already been exceeding that power level with factory production 454 blocks, so I was even more mad. By the time that block from Merlin was finally finished I had already had the Gen 5 and Gen 6 BowTies bored to the 4.600 and fitted with the 4 5/8 and 4 3/4 strokers without not much problem.
Needless to say I was not very happy when I received my New Paid in advance Merlin II Block almost a year later and marked on it was these numbers ; " 1.190 Ht." That made me further mad at them. I did get it sonic checked and we did end up putting a 4.600 bore in it but if it had been a nitrous engine I would have been scared of the bore.
The Merlin III Block is supposed to be very thick now. It is also supposed to be made of better material.
The Merlin Pro Block has rasied cam tunnels usually and has billet main caps. IT also has only the .842 Chevy lifter bores.
Comparing the Merlin Pro Block to the lower price ranged Dart Sportsman Big M or the Sportsman Billet cap block the Dart wins in my books. Plus Dart still has the Dart Race Block that is really nice.
Ed