Was there ever a difference on flywheels? I have a 230 that is at the machine shop getting balanced. I pulled a crank out of an unknown year 250 and I have the flywheel from both engines. My 230 is already cleaned up, the 250 is pretty rough.
Well, I hope they are the same because my 250 crank, 230 rods, and 230 flywheel is getting delivered to the machinist today! Should put me well on my way to building the bottom end.
They are the same. My 153 is using a V8 flywheel. If the bolt pattern works it;s OK. There are internal and external balance with the V8 and there are 153 and 168 tooth ring gears. You'll be fine.
IIRC the 400sbc is the only one that has a factory balance weight on the flywheel. All the rest of them, 194-230-250-292 and 283-307-327-350 can use the same flywheel, either 153 or 168 tooth. Balance is the same.
But you have to make sure the starter & mounting holes match the flywheel you have, either the 153 or the bigger 168 tooth.
One other catch, some of the 292 used 7/16 bolts and some used 1/2 bolts. IIRC all the 194-230-250 were 7/16 bolts.
If we were talking Ford here we would need an entire book to cover this topic!
That is correct, the SBC 400 is externally balanced.
Well, I have the starters from both engines so I should be OK even if I do have a different tooth count. The person who was supposed to deliver the parts apparently forgot, so it will be a couple more days....sigh....
The bolt holes in the block where the starter mounts will indicate which flywheel you can use. If the holes are in a straight line relative to the back of the block the 153 tooth wheel and starter must be used. Starter holes in the block staggered from each other will allow the 168 tooth wheel and starter. Some blocks have all 3 starter holes but they are rare.
Additionally the bellhousing that is flat down the starter side will only accommodate the 153 wheel & starter combo. Bellhousing with a bulge on the side for the starter nose is for the larger wheel set up. It is possible to drill and tap the bottom of the block for the needed starter bolt hole to match your flywheel size and starter mount. The outer bolt hole is the same for both. The inner hole closest to the crank is the one that differs. If you do drill the bottom of the block be absolutely sure of its position or starter drive and ring gear problems will occur.
Good info! All my parts are at the machinist, just sent the bearings out today for balancing and setting deck height. Can't wait to get it back and put it together!