I'm getting a project thirdgen very soon! Im beginning to research my options for engines. Since this would be my first chevy v8 build, I was thinking a basic mild 350 (350 hp). But I have several experienced mechanics in the family and friends who would be willing to help me with a more complicated hi-performance 383/400 (450+ hp 450+ ft/lbs) build.

Looking up the 400 blocks I've found the 4 bolts raise PREMIUM. However I have heard that the 400 2 bolts are stronger then 400 4 bolts, something about how the 4 bolts crack main caps. Is this true, and how much difference does it really make?

If my goal was roughly 450 hp and ft/lbs would a 383/400 be better suited. Whats the difference between them in money/skill to complete/longetivity/potential/etc. And would a cast bottom end(with hyper. pistons) get me tehre safely, or should I invest in much more expensive forgerd parts?

Im sorry for all the questions but the search feature is not working, and I would like to get a plan before diving into a project.

 

450 ft-lbs of torque out of a stock 2-bolt 400 is a walk in the park, almost automatic. 400 HP is reasonable with a stock bottom end. I would strongly recommend that over a 383 if you can find a block.

At that low of a power level, the stock crank, stock rods, and hyper pistons would be fine. However if you plan to build something that makes meaningful power at above 6000 RPM, forged crank & rods would be a good idea.

Spend your money and attention on the heads. That's where power is made, especially in a big-inch motor. DO NOT think you're going to get anywhere with stock 400 heads. Heads that light up a 350 are barely enough for a 400.... remember, it's 15% more cubic inches, which means you have to move (flow) 15% more air at any given RPM as compared to a 350.

 

Ok good to hear that I dont have to worry about which block. But are the 4 bolt 400s actually weaker then 2 bolts? The blocks run a hundred to two hundred dollars more than a comparable 350 on ebay, so I just figured I would go for the extra cubes.

This is going to be a daily driver, well in good weather at least. So I would rather have an engine with more cubes, just for the fact that I wont need some major cunning to negotiate high traffic areas(read: big cam). This also means that I cant drive an 800hp car, nor would want to.

Im still not sure what I am going to do. So far my plan is to have it ready to drive this time next year, with a car budget of about 500+$ a month. So with roughly 6+g's to get a working car in a year it looks like I have a lot of options. So my budget if broken down is...

1.5-2g's t56+xmember+clutch+various other parts for swap
500$-1g various car expenses, like seat belts, nuts&bolts, exhaust, etc.
1g-1.5g's suspension, tires, subframe connectors, roll cage.
2-2.5g's Engine.

Well 2000$-$2500 for a 350/383/400 is do-able since I have access to lifts and tools already. I really have to be price consious though, if I spend 2000 dollars on a forged bottom end, I dont have any heads! So thats why I am looking at a cast bottom end, and penny pinching, which should leave me with a grand or so for heads.

Any recomendations on parts/heads for a mild 400?

 

Get a 2 bolt block. If you're really worried about the bottom end, have studs installed then have it line honed (must be done when converting to studs).

My BBC is only a studded 2 bolt. I've damaged a few engines in the last few years but never hurt anything in the bottom end.

 

the 400 is a great choice, and yes, the 2 bolt is stronger than the 4 bolt because of the larger bores.

don't mess with buying a bare block, though. for a street car like you described, gobs of torque and peak hp below 5,500, 6,000 rpm will be best. the beauty of that is you don't need an expensive "bulletproof" bottom end for a low revver like that.

there's an engine rebuilder i spoke to in washington state (have to find www and phone number) who would build me a 400 short block with arp rod bolts, hypereutectic pistons and a 1 year warranty for 795.00 + a 100.00 core charge.

i don't believe you could duplicate that by buying the parts separately.

you could start with that shortblock, bolt on a set of good heads (you can get vortecs from scroggins dickey with the cut seats and stronger springs for cams over .450 lift for less than 600.00) cam, intake, headers, ignition and induction of your choice and you can easily make the hp/torque you want for well under 3,000.00 and have a great, reliable combination for a daily driver.

the only problems you'll run into with the 400 are you can't run a roller cam in the 400 block without an adapter kit and the crankshaft has a 2-piece rear main seal. if you have a manual transmission, you'll also have to get an externally balanced flywheel.

if you like a 383 better, wheeler motorsports sells a great shortblock for 1,395.00 outright. car craft used one in a project a few months back and mader serious power.

http://www.wheelermotorsports.com/shortblocks_perf.html

 

OK, 2 bolts are cheap(er). Since this is mostly for street use, I dont plan to venture past the 6k region. I am planning on using a t56 manual eventually, and I understand that I need a special flywheel.

O speaking of trannies, the project car i'm looking at comes with a v6 auto tranny. Is it possible to cheaply use this with the 400 temperarily until I can get the parts for the t56 swap? If not I may just get a t5 from a junkyard temperarily until I get the t56, and drive very gently.

While im pricing out the bottom end, whats this 400 crank with the 4" stroke about? A 427/434 sbc WHOA!!!!! I gots to get this! Can a cast crank live through that kind of torture? If it can, does any one know of a company who currently makes 4" stoke small block cast cranks. I only say cast, because forged is out of my budget . Maybe I'll just rebuild a 350 and save up for a kick **** 434. Darn choices!

Thanks Garrett.

 

From what I understand a 4" throw will hit the cam. You can make a 454 small block, but it requires a specially cast block with a raised cam and thicker walls. A 350 will make 400 HP standing on it's head with the heads being the biggest part of that. There are things associated with 400s that kind of make them a pain. The siamesed cylinder walls don't promote good cooling, and depending on how much you want to spend on balancing, 400s are generally externally balanced. Stock rotating assemblies on 400s also have higher piston accelerations unless you get longer rods. They were designed as work horse low speed, low po, truck engines. Steve has been running 400s forever without a problem, so he is definately the most knowedgable. Until you start putting parts and prices down on paper, it's going to be hard to pick a small block. Especially since you're on a budget.

 

Couple of things to help you get in the right direction:

generally, the 2 bolt blocks are slightly stronger becuase the casting in the webbing area is not very thick, and the additional 2 bolts in a 4 bolt cap punch through the iron creating stress points at the bottom of the bolts. I agree with everyone above, the 2 bolt is a better choice if you can find it. This also allows future upgrades to a splayed 4 bolt cap, which is even stronger with none of the straight 4 bolt side-effects(though pricey for machine work(align-honing). Studding the bottom end with also increase the strength of the assembly, and is a wise investemnt, for not alot of cash.

A small block 400 will not bolt to a v-6 auto trans in an f-body(2.8L or 3.1L), the bellhousing is different. It will bolt to a 4.3L trans, they have the same bell pattern.

A stroker crank will require special machine work to clearance everything for that crank. This does not play into you pricing you have above. If you have your heart set on it, expect to pay more for this. Including, possible small base circle camshaft, pricey rods, and machine work to the block. Custom-priced pistons(not custom, but very low volume, so the price is generally higher). A better bet with a stroker is to buy an assembled short-block. Usually pricing is better, and the gotchas are taken care of.

whatever heads you deside to use, be sure that they have steam-holes drilled for a daily driver.

overall, if you are a dedicated engine guy, building the motor from scratch is cool, and can be built to specifications you create. If you are not intimately familiar with the engine internals, and have all the necessary tools to check for tolerances and clearances, you're going to be better off in the long run($$) purchasing an assembled short-block for two reasons: probably will be cheaper and have all the misc. nuts and bolts and extra hardware that is always forgotten. and usueally, there is some sort of warranty. Hope this helps. Not trying to derail your effort, either, just have seen alot, and trying to make the swap as easy as possible for you.

 

Well, as far as using a v6 tranny with the 400 block, it wouldnt work. The v6 tranny has a different bolt pattern than a v8. Im sure you could find a cheap t-5 for 200 buck to hold ya over as long as you dont rough it.