Sure, the Chevy small block is the world's best engine for interchangibility. There are some little differences that you should be aware of. Here are my three:

Exhaust channel in intake. Early Qj manifolds used an exposed exhaust channel under the carb. Must use 3 piece gasket set to seal. The stainless shim goes in the middle.

Oil pump bolt. Early smallblocks used a longer bolt to secure the pump. 2 3/16" for the early ones, 2" for the later ones. Get it wrong and you could fail the rear main, or have the bolt pull out!

Steam holes. 400 small block heads must have a steam hole drilled. Use a head gasket for a pattern.

In each case described above, everything bolts together fine, but if you don't catch your error you may soon be in the market for a new carb, set of heads, or crank!

Uncle,

Here's one that caused me alot of grief until I found out. The early SBC harmonic balancers timing mark is 10 degrees different than late 60s and later marks. If you install the wrong balancer with a stock welded timing tab, you will be ten degrees retarded from where you think you have it set.

The early small block heads (50's) had irregularly spaced bolt holes for the valve covers. Not sure what year they stopped this.

Threw me for a loop once when I bought aftermarket valve covers for a 283. "What year, sir?" "It doesn't matter, they're for a pre-86 small block chevy! They're all the same!"

So I had to go back to the parts store for my serving of crow.

Some sbc heads didn't have acc holes in them also...

One thing I found is with -186 head castings. Everything I've seen written calls these performance heads with either 1.94 or 2.02 intake valves. I pulled two pairs of -186 heads, one pair from a 69 235 hp 327 and another pair from a 350 in a 69 C-20. Both had 1.72 intake valves and what appeared to be 69cc chambers.

The 400 uses a unique flexplate and harmonic balancer (the engine is externally balanced). No 400 was ever made with a manual transmission. If you are mating a manual transmission to a 400 you must use an aftermarket flywheel made specifically for a 400 sb application.

I belive the early 55-57 blocks did not have provisions for motor mounts on the side of the blocks.

The 283/327 Chevy II blocks are different.

Not all cranks are drilled in the ends to accept a dampner bolt.

Some 283 blocks will accept an SJ 327 crank and some wont.

Not all "010" castings are 4 bolt mains.

The first of the 1955 blocks did not have provisions for a block mounted oil filter.

The 1955 to 1966 timing chains were wider than the 1966 and later ones.

I thought of something else. While the oil pans may bolt up to the block, they won't necessarily clear the chassis because of differences in various cars.

Early blocks also have the crankcase vent hole behind the intake manifold. I've had to plug a couple to run PCV out of the valve cover.

I had a SJ 327 with no provision for the clutch ball. NONE AT ALL. Apparently the truck blocks mount this on the bellhousing. I had 90% of a motor swap done before I noticed that little gem. graemlins/angry.gif

Some timing covers take a thick front lip seal, some take a thin one.

Some SB's have LH dipstick, some right hand.

You got small journal blocks or large journal blocks

Some later blocks aren't machined for a mechanical fuel pump

Some later heads use the center bolt valve covers

Some later heads have the intake bolts at a different angle, and Vortech heads have yet a third different intake bolt pattern

Mike told me about the one that got me before - the thick or thin rubber oil pan seal on the small blocks. Did they change somewhere in the 70's? I can't remmeber..... smile.gif

chris

Aligned honed/bored 400's need to have the rear main seal shimmed or an oversized one. The main bearings are the same dia as were the rear main sits and it too gets honed by the boring bar :( .

My smallblock heads have 7 tapped holes for exhaust manifold mounting as opposed to the normal 6

TJ

Think the '55/'56, 265's and early '57, 283's had to have either a special rear cam bearing like an early 396 BB or else a good sized flat or annular groove machined into the rear cam journal??

This allowed oil to get to one side of the lifter bank, at least, I think that's what goes on???

pdq67

Very early SBs used a rope rear main seal.

Plain Jane factory right and left valve covers aren't interchangable, the rockers will wear holes in them and sound funny too. Too long a bolt in the hole in the front right side(pass.) of the block will pinch the fuel pump drive rod.

Cant forget about the short water pump and long water pump as thier different pulley arangements.

The canister oil filter and the spin on filter.

The straight vs slanted water outlets.

Early bellhousing mounted starters and later block mounted starters.

Early internal balance and later external balance and of course the 400 balance.

153 and 168 tooth flywheels and flexplates.

400'S use a different oil pump drive than all other small blocks. The diameter is reduced in the mid section for clearance.

Jeff65SS

'64-'67 Novas used a different oil pump, pick-up, dipstick, and distributor drive rod. The oil oump bolt may have been different as well.