455 Buick Rehash

10. This motor will use stock iron exhaust manifolds for improved convenience, price, fit, and sound over headers for this mild driver. We rescued them with, again, the Eastwood sandblaster, then used a disposable foam brush to paint them with Eastwood's High Temp Coating in a new color: Cast Iron Gray. The coating gives a long-lasting as-new finish that cures with heat once the engine is running.

11. Now for the techincal part of the rehash: The stock timing chain was floppier'n a puppy-dog's ear, so we threw on a new Speed Pro unit. The Speed Pro performance chain was actually cheaper than the same-as-stock version, so guess which one we bought. The PN 220-4115 chain set is single-row but with four-degree-advance-and-retard keyways; we installed it straight up. Speed Pro PN 220-3115 is a double-row chain, if you prefer. According to Buick Performance Engines by Steven L. Dove (available through Poston Enterprises, and mandatory for any first-time Buick builder), all curent Buick three-keyway timing chains are mismarked: the 0-degree, straight-up keyway is actually 4 degrees retarded, so you have to install the chain on the keyway marked as 4 degrees of advance for it to actually be "straight up." We found this out too late to verify it with a degree wheel.

12. Whomever designed the Buick timing cover was sniffing glue--similar to an AMC design, the steel oil-pump gears in the soft aluminum housing were not a great idea. Again according to Buick Performance Engines, acceptable oil-pump-gear-to-wall clearance is 0.004 or less. If it's 0.008 or more, chuck it. You'll also find that corrosion has probably eaten the aluminum in the water passages. As a result, all the good housings were already harvested from our local junkyards. Buick specialist Poston Enterprises sells expensive new timing covers and cheaper good used units like the one we got (right).

13. To save the oil pump, we used Speed Pro gear kit (PN 224-519) and plate kit (224-518TP). The first kit includes new pump gears, check-valve springs, and gaskets, and the second is a steel plate that can be added if the aluminum thrust surface of the oil-pump cover has too many grooves worn in it. Buick specialists also offer several styles of long-gear pumps and deep covers for high volume. The arrow points to an oil-pump-cover-bolt location under the filter that you may overlook if you don't know it's there. Also, this type of oil pump should be packed with petroleum jelly (Vaseline) during assembly to make sure it will self-prime when the engine is fired.

14. To install a new Speed Pro neoprene front seal in the timing cover we had to file off the tangs that hold in the original rope seal. When installing the timing cover, we aligned the mark on the balancer with the timing mark that indicated 12 degrees BTDC, making sure the number-one cylinder was on the compression stroke. That way, all we had to do was install the distributor such that the rotor was pointing directly at the number-one terminal in the cap to set the initial timing at 12 BTDC for initial fire-up. Easy.

15. Here's a new thing we learned about Buicks: Through '69 models, the 400/430 engines used a short-style water pump shown on the left; the '70-and-later 455s have the long style shown on the right. We converted our '72 engine to use the short pump, which makes the 455 fit better into early A-body cars. We asked an auto parts store for a '68 Riviera 430 water pump and got the right one. The old long-style alternator adjuster bracket can be maintained, but we needed to buy short-style pulleys.

16. Before installing our new Edelbrock Performer intake, we found that Speed Pro had two listings for 455 intake gaskets. At left is the PN 260-4013 gasket, typically used with '70 blocks and heads without smog passages; at right is the smog-style gasket (PN 260-4023) that was required for our '72 engine. While we didn't need to remove the heads on our engine, also note that 455 water passages changed from '72 to '73, and the '73-and-later heads will leak water when used on a '72-and-earlier block unless you make some mods outlined in the Buick Performance Engines book.

17. Here's the view of the intake surface of the '72 smog heads with the air-injection holes indicated by arrows. The instructions with the Edelbrock intake indicate that these 5⁄16-inch holes need to be plugged when installing the Performer, which does not incorporate the cast-in injection rails as the stock manifold did. However, the holes only need to be plugged if using the early-style gasket with the late smog heads; if you use the later PN 260-4023 gasket, the smog holes will be sealed sufficiently.

18. This will give you an idea of where the smog injectors are in the '72 intake, and also reveal why we couldn't bear to reuse the stock intake. It's huge, heavy, and ugly. The Edelbrock unit will save pounds and add performance.