[Dizturbed One]

Upon ripping the motor down to the bare block I find there is some decent scoring on the crankshaft, but I can still see crosshatch on the cylinder walls from when it was "rebuilt" (that's all the guy said when my dad bought it)

As I look closer I see on the bottom of the rear main sleeve the numbers ".010" are stamped on it.

The same goes for the back of the block which I found after I removed the flyplate (but I read that might mean the nickel content of the block also)

I bust out my SBC parts book and find that the connecting rods are also the style used on a 400 crank (This IS a 1980 350 block though)

take a closer look at the pistons and they have ".060" stamped on them. Would that bring the bore out to make it a 383? I'm guessing YES by all of the other indicators.

It looks like the crank journals have been machined also, because the walls around them have grinding marks and they don't show the scallops below like the book says they should, even though the scallops are still on the front end and the surrounding block looks correct. Would the .010 on the sleeve I pulled be how much this was grinded? What size bearings do I now need for the crank? And do I have to get a 400 crank ground to the correct size?

This is my first build, and all of this new knowledge AND the confusion of finding out that this motor is not stock at all but has been built for at least mild performance is making my head spin.

I also found that the heads are 76cc chambers. (The identifying mark on the side is a right angle triangle)

The deck hieght looks to be 10 inches on the dot, but I've only checked it with a tape measure.

The timing set is a clevite double roller chain.

The rockers don't appear to be stock either.

We ALREADY ordered and paid for a 268H Comp cams set with timing and lifters, and thier Magnum Roller Tip Rockers (which we assumed would be going on a stock 350). We also ordered chromoly pushrods...

How much trouble am I in... What do I have to take back and exchange, and what do I have to get in it's place.

Any more information you need I can get. I have all the numbers and measurements for everything I have. I can even take pictures.

I'll never do anything for an engine ever again until I have it ripped apart.

THANK YOU to anyone who can help me, I need someone who really knows there stuff.

[Lonestar]

Clarify what you mean by 400 style rods.

The pistons are .060 oversize which means that you are at the limit on a 350 block.

A 383 uses a 400 crankshaft and 350 bore.

My thought is that you have a 350 that was rebuilt as far as the cylinders will allow.

Need rod length and crank throw specs to be sure. What is the casting number on each?

[rick458]

Why do you want to "Destroke" it and loose all that torque and power?
the 268 will just work better, just polish the crank and put in new Main bearings

[BOBCRMAN@aol.com]

The crank= what is the casting no.? Next, what are the sizes marked on the back sides of the existing bearings?. I think you are saying .010" on the rods, and .010" on the mains. This means it was reground. A 400 crank uses the same rod journal size as a 350. If it is a 383 then the casting no.s on the crank will reveal what you have for a crank.

Again, the .060 is the overbore of the block. Indicating it was re-bored. This is the maximum bore size for a hi-perf 350 block. The bore doesn't make a 383. The stroke does. a .060 bored 350 is about 359 cubes.

[Lonestar]

Originally Posted by Dizturbed One

The deck hieght looks to be 10 inches on the dot, but I've only checked it with a tape measure.

Hello, what do you mean?

[camaroman7d]

WOW!! You had a lot of info in there but, it was scattered. How do you know it is a stroker? How did you measure the rods?

Now, if the block is bored .060 over (judging by the pistons) then you can't bore it any more (typically). If the hone marks are still there I am sure you can probably get another build out of it (at the .060 bore).

Using 400 rods (5.565") is the way 383's were built originally, there is nothing wrong with that. a longer rod (5.7") is better but, the short rods work fine too. We won't go into too much detail and get you more confused than you already are.

A 350 block with a 400 crank (or aftermarket 3.75" crank) and a .060 over bore is a 388 (not a 383). Basically the same thing. If the crank is a 350 crank (3.48" stroke) and it is bored .060 over you have a 360. Judging by the rods (if you know for sure they are 400 rods 5.565") then I would say you have a 388.

I am not sure what "sleeve" you are talking about? Are you talking about bearings? The 010 on the back of the block is nothing to do with machining that is a casting number.

If the crank is scored you will need to have it turned or at the very least polished, at that time the machinist can measure the crank and tell you what size bearings you need.

I think you need to seek someone local that can take you under their wing and help you get this thing figured out. Either that or haul it all down to the shop and pay to have it sorted out. It will be MUCH cheaper in the long run. If you want to do it yourself that's great just research before you go any farther. Not just on the internet but, go out and buy a good small block Chevy book "How to rebuild your small block Chevy", "How to hot rod your small block Chevy", etc... There are several to choose from.

Instead of looking at marks on the heads/block, etc... go to www.mortec.com and look up the casting numbers to figure out what you have. there is also a lot of good reading on that site for you.

Royce

[bracketeer]

The number .010 on the rear main sleeve would be .010 over bearing. Designating the crank mains have been turned 10 thou. If you look at the back sides of the rod bearings it will tell you what size bearings you have thus what the rod journals were ground down to. Since you have crank scoring. You will need to turn the crank again. The machine shop will tell you the sizes.

The reason you have 400 rods is because you have a 400 crank in a 350. The 10 on the back of the block maybe designating that the macine shop line honed the mains to fit the large journal 400 crank.

The .060 on the pistons designate a 60 thou overbore on the cylinders. This is pretty well max on a street motor. Your block may be a dead issue depending on cylinder wear.

A 76 cc head is a low compression head. Real low if you have dished pistons.

Any parts you ordered can fit on another block.

My opinion on this motor would be to scrap it. Get another 350 core. The heads are not really worth doing anything with. You can get some 70cc aftermarket iron heads for $500. Aluminum heads for $1000. The crank can probably be turned to 20 thou. Go to a 5.7 rod. It's cheaper and works better. Get flat top pistons to fit a 400 crank with 5.7 rods.

[lluciano77]

It sounds like you may want to find another block. If I was building a 350, I would start with a late model block.

The 268H cam doesn't work well with 9.5:1 or more. Your 76cc heads will lower the compression into that range, depending on the piston you use.

[Dizturbed One]

I have a smallblock Chevy parts book and it gave two photograph examples of connecting rods. Those for a 350 crank and those for a 400 crank, and mine match the picture in the 400 crank in several aspects (bolt heads, the machining lines across the rod mating surfaces, thicker rods)

The block casting # is 3970010

The Intake Manifold number is 346249 (It also says 249 EGR on the bottom, will an EGR intake cause compatibility problems in the 63 Bel Air Wagon it's going into?)

The Number on the crankshaft is 3932442 and it also says GM32 on another counterwieght the date code (I believe thats what it is) is K23 2

The casting number on the cylinder heads is 462264

The only numbers I could find on the cam are spread around. By the distributor gear it says EP6 on one side and I-5 on the other side. And it says CWC (manufacturer?) about halfway down the cam.

Will I have valve clearance problems with the cam we already ordered? Are these heads sufficient for this cam also?

And with this motor having already been built and bored out to maximum levels and using these heads will we still be running pump gas? (doubt it)

All kinds of stuff I need to know, anything else anyone can think of would be appreciated.

[Derkyb]

If ti was a stroker wouldnt the block be notched?

[BOBCRMAN@aol.com]

You have a 359 442 is common iron 350 crank

[Lonestar]

Personally I think you had better get yourself some good books and start reading. Don't take it personally but to me it sounds as if you've never worked on an engine before. Educate yourself before wasting your time and money. There are a lot of guys here that will help (myself included).

You need to identify what you have first. Go to www.mortec.com (as mentioned before) and look up your casting numbers. Start there.

[Dizturbed One]

Also, I just want to know if I can put this motor together SOON. Whether the heads will perform good or not for right now is of no importance because in the coming months one of the first things I will do is put new heads and an intake on it. I just want to know if it will be fine to drive alot.

I have no intention of scrapping the block seeing as how the guy who sold it to my dad said it was recently rebuilt, had low miles, and I can still see the crosshatch design from the final hone on the walls. The fact that the block has been machined recently leads me to believe it is a good block and has been checked thoroughly. The piston rings all looked to be in good shape and the cam looked damn near brand new after I pulled it, the timing set looked to be pretty nice too with only slight signs of wear. No chips or uneven markings though, it's worn uniformly.

One of the pushrods was badly chipped, and the bearings on the crank had some pretty bad worn spots also, in some places turning a bronze or copper color, but the journals underneath look to be fine.

[lluciano77]

You gotta start somewhere. Hands on is the best way to learn. Hands on doesn't replace reading and asking questions.

[Dizturbed One]

Originally Posted by lluciano77

You gotta start somewhere. Hands on is the best way to learn. Hands on doesn't replace reading and asking questions.

Exactly

I have done ALOT of reading and ALOT of asking questions, both online and off.

The problem is that while I am not afraid to admit I am a total novice (I've only done a stock rebuild on the top half of my chrysler 383 and the same on a 350 in my cousins K-10 Blazer) everyone I talk to offline tends to think everything they know or say is 100% correct when several factors do NOT add up with they're opinions or knowledge.

While I might be a novice, I'm not an idiot... Far from it actually, I just need help and opinions, and I've noticed ALOT of cool people who really know their stuff on this board who I believe can help me out. (As a few people have already immensely done in this very thread)

You're right, I have to start somewhere.

And here I am.... Starting.