I was browing through the Summit catalog yesterday and was looking at the Bill Mitchell hardcore racing products rotating assembly. Well he offers a 383 a 415 and a 427. Does anyone know if I can run the 415 kit with my 4bolt GM replacement block?

 

The 415 and 427 require a 400 bore. So if that's what your block has, then yes. Otherwise, no.

 

Will I be able to use my stock oil pan?

 

It really isn't feasible to fit a stroke longer than 3.750" into a GM production(ie non-Bowtie/Rocket)block. Those engines have 3.850 and 4.000" strokes respectively. You could use those cranks in a 4.000" bore block. They'd net you 387cid and 402cid respectively, you'd just have to have a Bowtie, Dart, or World block. An aftermarket oil pan with spread rails would more than likely be necessay, even if it's not, it's still a very good idea.

 

Please expalin. I am confused. A 415 stroker kit will net a 387 cid(?) and a 427 stroker would net a 402 cid (?) "respectively"????

Why would it not be a 415 and a 427? They are made for a 400 block. The 400 block is designed for a 3.75 throw crank. You would then clearance for a 415 or 427 cid motor. If I am incorrect someone please............[nevermind].

:lala:

 

Most likely your stock oil pan would work. My 400 oil pan is the same as any other stock SBC oil pan (drivers side dipstick of course).

 

I said you'd get 387 and 402 if you threw the 3.850" and 4.000" cranks in a 4.000" bore block.

 

the problem with the 4.000" bore (350) block is that the main journal diameters are different. if you bought a kit like that, which can cost, you would have to bore the mains (thus weakening thier strength) or grind the hell out of the crank. so a 350 block with the 415 or 427 kit wouldnt really work.

If you have the crank for the longer stroke, your calculations are correct. I believe...(didnt calculate myself but think its accurate)

No offense intended. Just havent heard anyone talk about using a standard 400 main dia. on a 350 block. That seems to be the reason they produce the 383 kit. It has the 400s stroke but the 350s main dia.

I know you CAN do it...but is it worth it? I mean when it comes to the integrity of the engine....

 

A 350 has a 4.000" bore and a 3.48" stroke. A 400 has a 4.125" bore and 3.75" stroke. The 400 displacement is actually about 402.

Start from there. If you take a stock 400 crank and turn its main journals down to 350 diameter, and put it in a 350 block bored .030" over, you get a 383. It's also possible to put a 350 crank into a 400 block, by using main bearing spacers; this produces a 377 if the block is .030" over.

All sorts of people make cranks with other strokes to stick in these blocks. A 3.875" stroke in a .030" over 350 block is a 396 for instance. The same stroke in a stock bore 400 block is a 415. 4" stroke in a stock 400 bore is a 427.

The biggest SBC I have ever personally built was a 434, which is the 427 mentioned above, in a .030" over block. This was a stock production 509 casting. I can personally attest to the "feasibility" of putting such a crank into a stock block. We happened to use a Milodon oil pan on it because of owner preference (not mine - and because it was a 400 block, the high $$$$ windage tray Milodon supplied with it wouldn't work) but a stock pan would have worked just fine. Because of the rods we used, relatively little grinding was required. This was not "cheap", it was not a "budget" build, but it also was not what I would consider a high-dollar kind of thing. Any competent racing motor builder can do this. There is not an engine integrity problem when the correct parts are used, as any sprint car racer in a class higher than stock motor can attest to.

The same sort of thing can be done with a 350 block. The same stroke cranks are available finished to 350 main journal diameter. However, if you're going to spend that much money and effort on a custom big-inch stroker motor (around $2500 just in parts) then it makes no sense not to go the junkyard and pick up a $300 400 block. It's just plain stupid to leave 30 cubic inches on the table out of 434 possible (7% results) when you're spending money to get big inches, for $300 out of a total $5000 motor.

I have a regular early 70s Z28 oil pan on the 400 that lives in my 83 when it's not busy passing CA emissions. There is no difference between a 400 pan and any other LH dipstick oil pan.

I am a builder, not a magazine reader. There is a big difference.

 

So will a 4" crank fit into a prodution block?

 

407 stroker kit

Will this kit work in a regular block?

 

4" stroke in a stock 400 bore is a 427.

The biggest SBC I have ever personally built was a 434, which is the 427 mentioned above, in a .030" over block.

The same stroke cranks are available finished to 350 main journal diameter.

However, if you're going to spend that much money and effort on a custom big-inch stroker motor (around $2500 just in parts) then it makes no sense not to go the junkyard and pick up a $300 400 block. It's just plain stupid to leave 30 cubic inches on the table out of 434 possible (7% results) when you're spending money to get big inches, for $300 out of a total $5000 motor.

All quoted from the above post.

It looks like those kits are intended to go into a production 350 block. Never having bought one I can't say for sure, call them and ask. It's hard to say how much grinding you'd have to do to a given block to get one to fit. It's not like you just buy the cheapest one and slap it in like it was an air cleaner or something, and $1695 or whatever and one Sunday afternoon later, you've got a 407 instead of a 350.

 

You're right that if you go the same crank from the 415 and 427 kits that you'd have to grind it down, but I'm almost certain that Scat and others make 3.850 and 4.000" cranks in 350 main sizes. Dart also makes a 4.125" bore block with 350 mains.

 

"will a 4.000" crank fit into a production block?"

It depends on what you are calling a production block. If you want to put the 383 crank kit in a 350...yes. If you want to put a 415 or 427 crank kit into a 350...no (unless you feel the need to burn cash). I personally have not seen the 407 kit you speak of so I could not answer with any real knowledge.

383 kit ----> 350 block (4.000 bore)
415 or 427 kit ----> 400 block (4.125 bore)

But they all require clearancing the block. Does this answer your question?

Make sure you read RB83L69's post(s) a few times so you wont miss the "makes sense" answer. That is unless you are a manager at the company I work for. Then you dont want to make sense.