vallance

Hi all. I'm thinking about a project with my 15 year old son, who would love to build his own engine and might be a budding engineer. My 66 has body off right now, so it would be convenient time!

I would love to hear your advice on how to configure and purchase a good kit. It would be our first time doing it, but I'm a mechanical engineer and feel comfortable. I just don't want to spend forever researching parts and options.

I know i want a 383 stroker with ton of torque and over 400 HP, and I want it to fit in my 66 without alterations.

I would like to call a vendor that will help me make all the choices and ship me boxes of parts. I want to start with clean and machined block and build it up.

Any suggestions on vendor that can help me configure the entire kit to work with my 66?

Thanks, in advance.

- Ryan

kellsdad

Ryan,
Congrats on the plan. Here are my first thoughts.
Having changed engines in my Corvette some time back I suggest you consider some other factors before you decide on a specific kit. One of the basic lessons I learned is that every time I changed one thing from stock, it would snowball into ten other things. For example, if you don't keep the tach drive distributor, you have to do something about the tach. If you change the design of the heads, the exhaust may not fit right. If the new engine has a different intake, there may be hood clearance issues. ... My point is that you should sort out anything that will be different from stock before you decide on a kit. That may limit the options available to you. ... Good luck to you and your son. I'd love to see his face when that engine fires for the first time.

SWCDuke

You're asking a lot. The quality of the final product will be directly proportional to the system engineering that goes into it. I'm sure as an engineer you understand that.

For starters I do not recommend that you attempt to modify your '66 ...870 block for the larger bearing (2.45 mains) 3.48" stroke OE and 3.75"stroke aftermarket cranks. The '67 ...657 production block and OTC ...512 block were produced for both bearing sizes. They have thicker webs and bigger bearing caps. Both have the proper retention notches for either bearing size, so if you come upon one of the above that was machined for the small bearings, any competent engine machine shop should be able to align bore for the larger bearings.

You will need to do some clearancing with a 3.75" stroke crank, and it's best to use so-called "stroker rods" that will minimize the amount of block material that needs to be removed. Attempting to gain sufficient rod clearance with your OE ...870 block is risky and could penetrate the water jacket, effectively destroying the block. There have been many discussions on this subject, and it's much easier to search the CF than reinvent the wheel.

The ...657 and ...512 blocks are unique because they both have the rear crankcase ventilation port, so you can use the OE PCV system. Later big bearing blocks lack this feature because for '68 the PCV system was changed to in one valve cover an out the other, so those blocks lack the rear crankcase vent port.

With either of the above two blocks you can use the rest of the OE components making the engine layout indistinguishable to casual observation from original, but, of course, anyone who can read the block casting number and stamp pad data will realize that the block is not original to the car.

The 3896962 hot hydraulic lifter camshaft first used on the '70 350/350HP engine would be a good choice, but I'm sure many will try to convince you to use a roller hydraulic, which IMO is not cost effective and has some pitfalls. Again, lots of discussions on this topic.

If you want maximum power, massaging the heads is the best way to go. Its' not hard to do, but is time consuming. Get a copy of "How to Hot Rod Small Block Chevy's" and at least one of David Vizard's books on massaging SB heads. Any year within the era Chevrolet COM has the detailed disassembly/assembly procedure including useful tips like which bolts require sealer because they penetrate the water jacket or crankcase.

I've always said that everyone should have the experience of massaging at least one set of cast iron heads. You will likely never want to do another, but it sounds like you've got some "cheap labor" to do it as long as you supervise.

Duke

vallance

Hi all. Should have been more clear. I don't want to touch my numbers matching 327/350. I'll store it and do this for the fun.

SWCDuke

If you don't want to use any existing components from your L-79, but want it to look OE, then start looking for a 657 or 512 block. They're out there, but not real common. If OE appearance is not important to you then a common ...010 350 block should do, and with a little creativity you can rig up a pre-'68 type PCV system so you can use original type "Corvette" valve covers without having to molest them to install PCV inlet and outlet connections.

A better alternative might be a GM crate engine, but then your son won't get the experience of assembling an engine from the ground up.

Duke

GTOguy

Places like Jegs have bare blocks, rotating assemblies, heads, and all the rest if you want to roll your own. If I were going with a new block, I'd buy a Blueprint crate engine and save the hassle. Lots of options with this one. I'm running an old, home-brew 383 in my '61, and have to say that it is one sweet engine. Power all over the place, very good road manners, very easy to drive. Much more power than a comparable 327 or 350.

cv67

Summit sells what you need assuming the maching is correct.
Might wanna talk to some local builders they usually have good cores and can get you parts cheaper than you can. Always fun building your own he wont forget it!

turbodave231

I am doing what you are looking to do. This isn't my first stroker build and experience is helpful when attempting to build something unique. My latest effort is a 385 from early an 870 327 block.

If you select the components carefully, you will not have issues of getting even close to the water at the bottom of the bores.

I took a new 350 journal/internal balance Scat 3.750 crank and had the mains ground down to the small journal main size. I understand now that Scat will make this configuration on a special order basis.

I also used Scat 6.0' OAL I-beam connecting rods. These rods allow the most clearance of any rod in the stroker application. You will still need some notching at the bottom of the bore, but not as bad as you might think. Not even close to H2O! (sonic tested)

I used the L-46/L-82 350/350 Cam for this application. With the cam degreed in properly, the rods clear the cam lobes without modification to the rod.

Another thing that was very nice, You can buy the entire rotating assembly pre-balanced from Scat. I am a stickler for weight matching reciprocating/rotating components. I keep my tolerances +/- .5 grams. The Scat rods were VERY close right out of the box!!! far better than I have seen from other much more expensive manufacturers.

Crunch527

Summit / Jegs have what you need...buy good parts though...

I assume they have everything you need and none of it will require any machine work.

GearheadJoe

I love your plan to do this with your son. I built a stock-looking 383 for my '67 and wrote the two attached articles about the build process.

You have gotten some good advice here about planning carefully before you buy any parts. Two things that I think are important are:

1) Use a block that has the rear vent provision so that you can easily use the correct unvented '66 valve covers.

2) Use the best-fitting stroker rod that you can find. Note that both block clearance and cam clearance are factors to consider, so sometimes you have to trade them off against each other. I have carefully compared about 15 different rods for clearance, and the Scat Pro Stock, Scat Pro Comp, and Manley Sprortsmaster are among the ones with the best clearance.

Feel free to PM me if you have any questions about planning your build.

vallance

Duke and Gearhead Joe,

I kind of like your suggestions and the notion of making the 383 stroker look like the original L79. Where would I shop to find a '657 or '512 block core to take to a machine shop ?

- Ryan

GearheadJoe

The 1967 block casting 3892657 was used in millions of passenger cars and has the rear vent plus the desirable 350 features, such as the cast-in rod notches at the base of the cylinders and provisions for large-journal mains. While I did not know it at the time I wrote my article, the rod notches in the '657 casting did not appear until January or February 1967. So, it's best to look for a casting date after that point, and to visually confirm that any block you are considering has the notches.

The GM replacement block 3959512 was never used in production, but it was used for several years as a general purpose replacement block for warranty replacements. The '512 block was machined for either small-journal or large-journal mains, and for either 2-bolt or 4-bolt mains, depending on the requirements for the engine receiving the warranty repair.

The easiest way to find some candidate blocks is to simply do a search on the casting numbers on ebay. Right now, searching these two casting numbers on ebay yields 26 listings. There is a little-known method for creating a "saved search" on ebay so that you get an email every time a listing matching your criteria shows up.

Since blocks are heavy and expensive to ship, your local Craigs List is also a good resource, but most Craigs List listings don't include the casting number, so you have to ask them for it.

Lastly, lots of engine rebuilding machine shops have a "trailer out back" full of used blocks that could be used as cores for a rebuild.

Drothgeb

The come up on eBay fairly often. I picked up a fully machined 512 block last fall for only $550.

GearheadJoe

I just looked at the asking prices for 3892657 and 3959512 blocks on ebay and most of the current listings look overpriced to me. My personal view is that the appropriate price range for a standard bore, garden variety block is in the range of $300 to $500. Maybe a bit more if it has been cleaned and magnufluxed for cracks.

Some blocks are more valuable if the pad stampings are correct for a rare restoration project (such as a 1967 Camaro SS350), but a garden variety 3892657 or 3959512 is only worth $300 to $500. So, don't be put off by the silly asking prices that some people want on ebay.

I think the best deal is a local seller who has a greaseball 327 engine from a 1960's Chevy that has never been rebuilt. These are often available for local pickup for about $300.

So, try to be patient in your search and don't fall for the ridiculous asking prices on some of the ebay blocks. Keep in mind that any block you buy could flunk a magnaflux test for cracks and be useless. So, it doesn't make sense to pay big $$ for an untested block.

GearheadJoe

What is a Scat "OAL" rod? I have compared samples of the Scat Q-Lite, Pro Stock, and Pro Comp I-beam rods for stroker applications and the best choices appear to be the Pro Stock and the Pro Comp rods.

I remain interested in finding the "best" stroker rod for use in vintage 327 blocks. It turns out to be almost impossible to evaluate a rod without actually testing it. The sales literature for stroker rods is simply inadequate.

Drothgeb

Yep, a lot of them are over priced, but some are not. Like you said, you just have to be patient. Mine was magnafluxed, bored and honed, decked to .005”, line bored and cleaned for $550 to my door.

Locally, that’s about what the machining cost alone would have been. Not to mention the time it saved me picking up a block somewhere, hauling it to the machine shop, then picking it up after it was machined.

I also bought a forged 350 crank, manafluxed, cut and polished to small journal for $200 off eBay. Perfect match for the block. Just had to have it balanced.

Yes, ebay has some terribly overpriced items. But, it also has a lot of great deals. There are numerous machine shop workers that machine stuff they have sitting around, then sell it on eBay for less than their normal machining cost, just to make a few extra bucks. There are also a lot of vendors on eBay that sell at lower prices on eBay than they do on their own web sites.

Treat Ebay just like other marketplaces. If they have what you want at a fair price, great. If they don’t, look around somewhere else.

Drothgeb

To me, these are the best 327 stroker rods at a reasonable cost. The Scat Pro Comps with 7/16” bolts. This particular set is 6”, small journal. Plenty of clearance for a stroker.

Bought them on eBay for $275 shipped.

GearheadJoe

Yes, that is the Scat Pro Comp rod that I used in my 383 build. I selected that rod after searching the web for info on "best stroker rods".

Most builders have a favorite rod but few have done any kind of detailed comparison. It's a shame that the rod manufacturers don't have any standard way of specifying clearance for stroker rods.

One thing I noticed about the Scat Pro Comp rod that I used was that the shoulder around the bolt forced me to remove more block material than would have been necessary for just the bolt head itself.

After I built my 383, I continued to wonder whether there might be some rods out there that have even better clearance than the Scat Pro Comp. I collected samples of quite a few candidates and measured them all by installing each rod in the same cylinder of a block I had on an engine stand.

The attached one-page summary is where my comparison stands at this time. You will see that the Scat Pro Comp is one of the better ones, but there are others that have more block clearance.

grumpy55

Look at Competition Products..
They list complete 383 kits, including block, rotating assembly, heads, intake, carb, ignition . . .
All machined and balanced .

Mike C#2

Agreed, I like doing business with Competition Products. We are putting together a 72 Jimmy for my teenager and if we have issues with the 350 it will be getting the Eagle balanced street 383 kit. For $820 it's a deal.

BUT, if you are looking for more of a "max output" type motor, there may be better choices.