I had a 455 done years ago by a shop familiar with Buicks that still screwed it up. A guy working there was a former chapter member and had a GS running 12's (was fast at the time) and swore the shop knew Buicks.
It lasted barely 3000 miles and I was lucky to make it home from the Nat's in 1984.
It was a nice 71 block with nearly no wear in the cylinders, yet they said they needed to bore it .020 over. Ok, but no pistons were available so I had to go for a custom set of Arias forged that were $400 (1983 prices).
So, they went ahead and bored the motor. New cam bearings (no TA stuff at the time but they "knew" how to put them in right), balanced it, cut crank with matched bearings and put the pistons on the rods.
I get all the stuff back and start to put the motor together (not my first by any means). Line all the stuff up and 1 rod has the piston on upside down. Ok, back to the shop in NJ from upstate NY.
Washed the block with hot soapy water to make sure it is clean. Dry and oil it before assembly. All looks ok, ring gaps good and all that.
Put a new Kenne Bell timing cover/pump and "assumed" it would work (first mistake).
Pump binds up on startup. Bends dist. shaft on an NOS Stage 1 dist. (yes 1112016) and didn't know it.
Fix clearance problem and put new pin in dist. Motor runs but sounds like an Olds diesel. Warms up and gets quieter as pistons expand. Drove it to the nats after break in. Low on power for a KB 118, B4B, KB Stage 3 heads and KB headers with 3.42 gears. How's 13.9 to low 14's sound.
All this for $3000 at the time and telling the now ex-wife (one of the reasons I am sure) that this will be the "last" motor I will have to build.
Back home and the motor noise is getting worse. Turns out the Arias pistons were also made for blower applications (bbc Chevy units cut to Buick, said 427 under the pistons) and were set to .016 clearance with a .020 overbore. So by boring the motor before getting the pistons (experienced shop ) there was major piston slap.
The rest of the noise was valve clatter from the drivers side (sound familiar) due to the melting of the cam bearings.
Take the motor apart and there is so much gunk in the pan it is unbelievable. The shop tells me I must have left a shop rag in there.
Also that I must have assembled it wrong. Won't even comment on the piston slap issue.
Car now has a bone stock 70 Riv motor
and headers with NO motor mods and runs 13.6's .
The shop was Haledon Auto Parts in NJ and I still warn people to stay away.





Buick Parts Directory 2004