????????????? Ok, normally you install a larger stroke crankshaft in an engine to GAIN cubic inches. You say you have a 406, so that's a 400 + .030 bore, the 400 is a block that can't safely be bored more than .030 w/o running into problems.

You're only alternative with this block is to buy an aftermarket ($$$$) larger stroke crankshaft which will require aftermarket ($$$$) connecting rods and pistons....among many other things. I think the most you can go is 434 but most guys go for a 421. Basically it's a LOT of money for not a lot of extra performance. You need to do sme research prior to making a decision, you can do a search function on this forum also for this modification.

 

A 400 with a 4" stroke is a 427 like in the new Chevy motors.
Like F-BIRD'88 said there are other things you need to make it run, esp some good heads
Save and get what you need in quality parts or it will nichol & dime you more than getting the right combo to began with.
In the Knowledge Base there is a site called Ryans Place and he gives different combos just for some ideas and what you will need to make it run.

 

i have a sbc 406..im looking to rebuild it to make a stroker motor but not a 377 what do i have to do? thanks for the help..

Leave it a 400 (plus whatever overbore may be needed needed) and concentrate on the top end- that's where the power is. Make the bottom end as durable as you can afford (think about after market rods 5.7" or 6", freshen up the stock crank, new pistons- forged if you are really going to lean on it or use nitrous, bearings, timing set, oil pump, gaskets, etc. and let that tell you how much rpm you want to run (a red line of 6000 rpm will still be enough to make good power). Choose a cam based on the engine bottom end and the rest of the vehicle, i.e. gear ratio, stall speed, weight, intended use, etc.

Remember- the engine is only one part of the whole. The rest of the vehicle has to be up to the task or all you will end up w/is an ill-mannered, tire shredding parts breaker of a money pit. Do it right and you can enjoy a 12-second ET capable high performance vehicle that can be daily driven and that's a joy to drive.

 

We've built a few of the 4" stroke versions. They "refer" to it as "427" in an attempt to tie it to the "real" 427 of yore. TOTALLY different animal. In reality, it more closely resembles the Ford and Pontiac 428s (bore/stroke, 4 1/8" x 4"). It's more of a "smaller bore, longer stroke" type than 427, as are the LS engines. (for clarity and separation from the Mark IV "big block" 427, 4 1/4" x 3 3/4")

I really "like" the 412 "kit" Eagle sells. The stroke is only a little longer at 3.8". But the crank is tuff stuff.

Agreed with Cobalt327, the factory crankshaft is up to the task. It's a good nodular casting. I wouldn't recommend any of the aftermarket castings for any more than pickup truck use. Using the word "steel" is misleading. In our business, a "steel" crankshaft is forged, not cast. MANY good forged cranks available for this.

GOOD cylinder heads are imperative. The 400 block is flimsy enough without adding cheesy castings to the top. Iron heads can make a big difference for a street engine's durability. The valve train must also be first-quality for the same reasons. Any and everything you can do to "stiffen" the block is a good thing. "Filling" (like "HardBlok") isn't a bad idea, but requires the use of a remote oil filter and external oil cooler to be safe. Most of the combustion heat is in the top 1" or so, but the oil can't reach the water jackets "up top". Using a cooler "fixes" this issue. Start with a 2-bolt block!!! If you install 4-bolt caps, be certain they're of the "splayed-bolt" type, NOT the "straight". The outboard bolts in the "straight" version go right into the already weakest part of the block. The splayed-bolts draw into the "V", the strongest part in the area.

Your HP and torque "requirements" will determine the "level" of parts you need to make it "go" and make it "live". What's it going in and what do you want it to "do"?

Jim

 

its a street car.right now it has cast heads with 202/160 it also has 373 rear end..i was thinkin around 411 416 ci. im just not sure what to do...

 

the cam now is a 480/280

 

keep 400

keep the 400 a 400. my experience is that the more cubes you have the more power you have. why would you wanna de stroke a 400 to say a 383, thats less cubes!

 

completed balanced sbc 406 forged rotating assembly 10.3.1 14cc dish piston 30 over 4.155 bore 6'' rods Skip white perforance

 

its in a 87 ss monte i just want a solid street car