406, 415, 421 or a 434 Stroker
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
A 415 and a 421 are pretty easy. 434 you are pushing the limits. It has been done many times. All of them will provide good HP numbers. Any one of them is going to need a real good set of heads to make power.
Drifting
Joined: Sep 2001
Posts: 1,427
Likes: 1
From: Boxford Mass
I didnt want to push it and decided to go with a 406.
The aftermarket blocks are built better for to handle the long stroke / big cube small block. A 406 churns out some good #s and will serve you well for years.
The aftermarket blocks are built better for to handle the long stroke / big cube small block. A 406 churns out some good #s and will serve you well for years.
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
I love my 427, could have gone with a 434 but did not want to overbore a new dart "little M" block. Figured in a few years maybe I will consider it after a put some wear on it. If I had to do it again, I prob would have dropped a big block in it or built a serious low CR 350 or 383 and slapped a super charger on it. Prob would have cost the same.
Race Director
Joined: Jul 2004
Posts: 12,706
Likes: 329
From: Scottsdale Arizona
I did the same as Jack and went with a low buck 406. I wouldn't want to rev it to 6000, but it melts tires from a stand still and I can even get away with regular gas in the cool weather.
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
I run a 511 block with Scat 9000 setup,balanced,but otherwise nothing fancy.Turns 7000 rpms,and has more torque than I could ever get to the ground with street tires.
My vote would be stick with a 406.Easy to get parts,plenty of power.
My vote would be stick with a 406.Easy to get parts,plenty of power.
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
I did a 406 with 5.7(350 rods) and it buzzed easily to 7000, I estimate it made around 450hp . Low budget parts like a scat cast steel crank, polished stock rods with ARP bolts and forged pistons. I used a cheap set of ported Dart torquer SR's and a lunati hydraulic cam. I even got a Victor JR to fit under a stock 81 hood. I built this all myself, my first SB build. I went to the track and got 12.96 at 113mph with a 2.1 60' which means no traction. So you can go bigger or do it simple, the HP difference will be minimal.
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Racer
Joined: Oct 2006
Posts: 435
Likes: 18
From: Florida
Well all and all, internals should cost the same. Maybe the only thing that will cost you is getting a good piston for the longer stroke and longer rod instead of an off the shelf part for a 415/421 stroker. Cost difference/offset would be at most $300.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
You can build a more inexpensive 406ci with cast crank, 5140 rods and hyperutectic pistons, it will last and save you money, lots of money. Once you get any bigger everything is forged and cost alot more. You can make killer power with a 406ci but you need good heads 
Le Mans Master
Joined: Oct 2001
Posts: 5,943
Likes: 3
From: Wildwood IL
My .02 is to keep the bore at .040 over (max) and stroke the rest of the cubes. I would not take a GM 511 4 bolt block to .060 over and expect it to live a long life. Keep in mind...Pan rail to rod clearance, cam clearance, deck height, and oil pan/pump pick up will be issues to deal with in a longer stroke motor.
Eddie
Eddie
Racer
Joined: Oct 2006
Posts: 435
Likes: 18
From: Florida
One last thing, if you want torque, go with the most cubes as you can since you will not be spinning it real high. If you want to spin it high than stay with the stock stroke and fit longest rod possible. It doesnt really help make power but it decreases side loading on these more fragile blocks. Minimum overbore to clean things up, keep as much meat between the cylinders.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Range of piston choices shrinks beyond 3.75" stroke.
AFAIK ... NO shim or thin composite gaskets avalable for sbc400 ( copper Not considered) ... plan on zero-decking.
Suggest you FIRST pick a compression ratio you're gonna be stuck with ... do your homework on gasket volume & block deck height ... then see what OFF-THE-SHELF pistons are readily available for the various strokes.
AFAIK ... NO shim or thin composite gaskets avalable for sbc400 ( copper Not considered) ... plan on zero-decking.
Suggest you FIRST pick a compression ratio you're gonna be stuck with ... do your homework on gasket volume & block deck height ... then see what OFF-THE-SHELF pistons are readily available for the various strokes.
Last edited by jackson; Dec 4, 2007 at 03:47 PM.
Heel & Toe
Joined: Oct 2004
Posts: 15
Likes: 0
406 Street Fighter
Hey you guy's...I built a small block 406 for my "73"..Two bolt,cast crank,ARP stud kit with Moroso windage tray,polished and peened pink forged Chevy rods,clevite bearings,weisco pistons,press pins,Comp roller cam 565"/289 /112 center line ,intake,11.23 compression with the Fel-Pro .072" head gasket,TFS twisted valve 13Deg intake with a 62cc chamber,air gap intake,with a quick Flow 750 and a Pertronix ignition ignitor..This combination is the ultimate street fighter secret of all time..There are very few cars out there that will beat you from light to light...won't matter what your transmission is ...A true Mustang Killer for Cheap..was only beat once by a very bad *** Mopar...Hey..I live in the Motor City...what the hell...RA
Thread Starter
Pro
Joined: Feb 2006
Posts: 649
Likes: 10
From: Shelby Twp MI
And the verdict is...
Looks like a mojority to go with a 406. The engine builder called me back, block is good but he said some of the threads look a bit "flat" and he recommended going with a studded block. He also said the block would clean up with only +.020 (so would that make it a 404?).
So, he said $2200 for a short-block with all the work to date, machining, forged steel crank, H-beam rods, forged pistons and one of those cutom-gound cams. For another $500, he would upgrade the build with a roller cam & lifters. Does this sound right?
Also, I do need to get him the heads and he'll bolt them on. I'm not sure where to go with this. He mentioned the GM FastBurns would definately live'n up the motor. Any thoughts?
So, he said $2200 for a short-block with all the work to date, machining, forged steel crank, H-beam rods, forged pistons and one of those cutom-gound cams. For another $500, he would upgrade the build with a roller cam & lifters. Does this sound right?
Also, I do need to get him the heads and he'll bolt them on. I'm not sure where to go with this. He mentioned the GM FastBurns would definately live'n up the motor. Any thoughts?
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Looks like a mojority to go with a 406. The engine builder called me back, block is good but he said some of the threads look a bit "flat" and he recommended going with a studded block. He also said the block would clean up with only +.020 (so would that make it a 404?).
So, he said $2200 for a short-block with all the work to date, machining, forged steel crank, H-beam rods, forged pistons and one of those cutom-gound cams. For another $500, he would upgrade the build with a roller cam & lifters. Does this sound right?
Also, I do need to get him the heads and he'll bolt them on. I'm not sure where to go with this. He mentioned the GM FastBurns would definately live'n up the motor. Any thoughts?
So, he said $2200 for a short-block with all the work to date, machining, forged steel crank, H-beam rods, forged pistons and one of those cutom-gound cams. For another $500, he would upgrade the build with a roller cam & lifters. Does this sound right?
Also, I do need to get him the heads and he'll bolt them on. I'm not sure where to go with this. He mentioned the GM FastBurns would definately live'n up the motor. Any thoughts?
It fits quite nicely in the 400 block also.