The parts list for building the 383 stroker engine for my 79 Corvette has now almost come to its final state. I must say that choosing the right parts has really been a pain because there’s just so much to choose from and every part needs to be Googled and checked through the forums. My friend Jim Barth from Salt Lake City, USA has given me a lot of help to build this 383 stroker and a lot of credits will go to him once the engine actually fires up. I certainly recommend him to anyone who wants to build a powerful 350 or 383 or any other Chevy engine.
Now here we go… first of all the short block. I took the original Corvette L-48 2-bolt main SBC 350 block out of my car and cleaned it up and removed all the original parts. The block was showing the usual wear on the cylinder walls and no factory honing marks were present anymore. It was as shiny as a mirror and also remarkably wider than it should have been originally – caused by the pistons over the years. Fortunately no big damages so I have sent the block to an engine shop where they will bore the original 4.0 inch cylinders over by 0.030 inches which will make the cylinder bore 4.030 inches – the proper bore for a Chevy 383 stroker engine. They will take care of the block and will also deck the cylinder head surfaces on the block by around 0.02 inches to make them straight and even and clean of all the old gasket remains etc. The important question now is what to put inside the short block – talking about the crankshaft, rods and pistons. The easiest way was to get a fine stroker kit which already contains all the important parts. I decided to go for the SCAT 383 stroker kit, already internally balanced in the factory with the included parts. The kit also contains forged pistons, the crankshaft is cast metal. The problem here in Estonia is that nobody properly balances a V8 engine and that’s why the safest way for me was to get an already balanced rotating assembly kit. In addition to the main components the package also contains piston rings, ARP rod bolts, oil rings, main bearings and a few other important components. What the kit doesn’t contain are the main cap bolts which hold the crankshaft in place – for these I have also decided to go with ARP’s. I’m yet to decide whether to get the standard strong bolts or studs.
The next important thing is ofcourse the camshaft. First of all, one needs to decide whether to go for hydraulic flat tappet (the factory standard for First-Gen small blocks), hydraulic roller lifters or solid roller lifters. I will write another article on the difference between them just to make it understandable also for the beginners (like I was a few months ago). However, since the hydraulic roller kit is 2-3 times more expensive than flat tappet and gives perhaps about 20-30 hp extra in my setup, I have opted for the hydraulic flat tappet solution this time. I can always convert to hydraulic roller set-up in a couple of years when I feel I need the extra power. When choosing the camshaft you need to consider the intake duration and exhaust duration at 0.050 inch lift. You also need to think about the valve lifts and lobe separation. It all depends on the components you choose and cannot be explained in one paragraph – it’s always easier to ask people’s advice in the forums like Hotrodders, Chevelles.com and Corvette Forum. In my scenario the perfect camshaft would be the COMP Cams Xtreme Energy 230/236 camshaft with grind number CS XE274H-10. When deciding on the valve lift the cam provides you need to consider the max. valve lift available on the particular cylinder heads you get. With AFR heads it’s 0.690 inches and the hyd flat tappet only lifts to 0.490. Plenty of room there and the AFR would actually feel more comfortable with hydraulic roller cams which lift the valves more. The 230/236 camshaft also provides the nice choppy idle while giving enough vacuum out of the engine to power the brakes and suck enough vacuum into the reservoir found on the 79 Corvette to lift and close the headlights. The particular kit from Summit comes with the Comp Cams lifters and double roller timing chain and gears.
Another thing to replace inside the block is the oil pump. After doing the research in the forums I’ve figured out that Melling makes the best budget pumps. For such engine it’s also important to get the high output version. There are stories that Melling’s pumps used to be good in the old days but a few years ago they changed their castings to cut on costs and this resulted in cracked and malfunctioning pumps. People still say that they’ve recently gotten rid of these issues and these pumps are anyway the best to get.
All the bolts on the short block as well as the rest of the engine should be replaced with better ones, preferrably ARP produced bolts.
Now the long block part which means everything above the block itself – cylinder heads and intake. I have decided to go with the Air Flow Research AFR 195 cc Street Eliminator aluminum heads which are pretty much the best on the market today for such an engine. They do cost more than the Trick Flows and even more than budget stuff like Darts, Edelbrock lower end aluminums, Patriots and such. The AFR’s produce more horsepower and torque in the end so the extra few hundred bucks might be well worth it. The AFR heads also allow for 0.690 inch valve lift so they are perfect with hydraulic roller camshafts to get the maximum out of the heads. The valves on them are 2.02 intake and 1.6 exhaust. These AFR heads already come CNC ported from the factory and there are people who port them even better to achieve the maximum performance. But note – when choosing the heads you need to check on the intake chamber size – 195 cc is the optimum for a street 383 stroker engine and 180 cc is better if you build a 350 or 355. The larger these chambers the more low end torque you sacrifice to achieve more horsepower in higher RPM’s. That’s cool if you go to the strip. But on the street you don’t want to keep the revs up all the time. That’s where the lower cc heads come into play. The 195 cc heads are perfect for a street 383 performance engine to provide the best of both sides – lower RPM torque and 6000+ RPM horsepower. Another factor on cylinder heads is their flow. This is different – the better the heads flow the more power you get in the end since the heads won’t be limiting the fuel mixture getting into the cylinders. That’s where many of the cheaper heads lack the good numbers. When buying cylinder heads it’s possible to get them in bare configuration or factory assembled. Bare means that you only get the heads and none of the springs, valves and other stuff that need to be on them, too. Assembled heads come with valves, springs and installed valve stem seals. Everything is assembled already for you and you just have to bolt them onto your block. This is the better solution in most cases unless you want to go with some specific components. Assembled heads are often cheaper than to order the stuff and assemble them all by yourself.
The hydraulic lifters come in the camshaft kit from COMP Cams. The lifters need to drive the valves on the cylinder heads and there you need to get a set of new pushrods. Jim Barth recommended the Trick Flow 4130 chrome moly pushrods which retail in Summit for about 120 bucks for a set of 16. You can ofcourse also buy new rocker arms but I believe I will stick to the factory ones since I won’t be revving the engine too much and the roller rocker arms are still very expensive. These are easy to replace items at a later time so I better leave these for the future.
To get the most out of the Chevy 383 stroker engine you should get a fine intake manifold to complement the great heads. Edelbrock produces pretty good aluminum manifolds and they can be bought for fair prices. Edelbrock Performer RPM intake is a good one although the Performer RPM Air Gap is even better. I couldn’t get the Air Gap because it’s even higher and won’t leave enough hood clearance with the 79 Corvette.
At this point I’m leaving the repaired Rochester Q-Jet 750 cfm carburetor on and I will get an electric choke add-on for it. I will also leave the factory HEI distributor in its place. Since the new engine will be revving a lot better than factory and there’s a danger to over-rev it and cause damage, it’s the best to get a rev-limited distributor. If you stick to your stock HEI like I will, you can get a special RPM limiter module from MSD or other ignition system producers. Better be safe than sorry, you know.
I am still about to decide what kind of flywheel to get since I’m building it for the 4-speed Super T-10 manual transmission at this point. I will write another article about it soon when I have gotten some more information and won’t be telling lies to you. Since my engine will be internally balanced, I need to get the harmonic balancer and flywheel to be zero-balance. The harmonic balancer will be probably SCAT Powerforce Series 8000.
I will soon write some more articles – first of all some clarifications about different camshaft and lifter set-ups and once I have the proper information, I will also tell you about the flywheel choice.