A few bits of advice on 400 s/b

....no replacement for displacement!

#1 rule "Don't bore more than .030"

#2 Drill the steam holes in the heads you install (match the gasket & you can do it)

#3 Only were built in the early 70's and most blocks are two bolt mains and are reasonably strong for most street performance applications with good main bolts installed by your machine shop.

#4 The stroke is 3.750 as compared to the 350's at 3.480.

#5 The stock rod is just a bit shorter than the 350's 5.7 Rod and no one builds 400 small blocks with the stock rods as they aren't as strong as the stock 350 5.7 rods.

#6 All stock 400 small blocks have cast cranks that are good to max 6800 and should probably be kept under 6400. Aftermarket cranks are available from 200$ to 2000$. Cast scat (don't like at all) to really good steel ones.

#7 All 400 small blocks were automatics and were never offered with a factory flywheel...only flex plates for automatics. Revised 4/24/01 to include 3986398 400 s/b external balanced flywheel (Thanks to info from Steve Master). No wonder I spend most of my time on Fords...

#8 all 400 small block cranks are factory external balanced. Lots of available SFI flywheels and flexplate for reasonable prices.

#9 If you have to align bore a 400 you will be using a special rear seal from Felpro 2909 as the stock rear housing bore is small and will be opened up with the align bore and need a different seal.

#10 If you want a fluid dampner then you will need a special Tavia timing pointer too.

#11 The crankshaft installed end play is critical on these small blocks....much more so than the 350's etc.

#12 It's not unusual to have to do a cam align bore on these blocks too, for .010 oversize OD bearings...maybe we have to do 3 out of 10. Be sure you shop can handle that and have them measure every bore b/4 they do the final clean and install the cam bearings and then have to start all over again...

#13 We can still buy completes here for 300-400$ that are rebuildable. (Nebraska) any racing in your area that involves IMCA Modified...you will find them there for sure.

#14 you usually have to jack the front of the car up when you fill radiator the first time to get the air locks out. This is typical with 400's.

#15 Aluminum heads (as mentioned above) are a nice option too.

#16 side clearance rods minimum .018 and .022 on the rear two rods.

#17 At least .006 end play on the crankshaft.

#18 drill the oil pump shaft hole larger to fit an after market oil pump shaft.

#19 Stock deck height is 9.025 and I like to deck to 9.010 to 9.015.

Well that's about it for the street 400 advice. Hope some of the basic facts about the 400 small block are helpfull!