I'll confese right now this engine is for my "other" driver. Its a big ol' 74 G20 -gasp!- van that I use for campin, haulin (I might get a greasy motor or trans in the trunk of my coupe but it just wouldn't be right- not the grease- the weight!) and general abuse. Its gettin to the age and milage that a rebuild is in order. A friend has given me the makings of a 383. Block, 882 heads, unmachined 400 crank ect. Would it be worth the extra expense/effort to build this? Im looking for touque and economy (who isn't) I'll admit its hard to beat the current 350/350 12 Bolt rear setup thats in there now. What do you think?
Probably would be cheaper to buy an aftermarket crank that's ready to go rather than pay to have the mains on the 400 crank ground down from 2.65" to the 2.45" 350 size. Well-worth it for the added low-end torque, a mild 383 build is less than $200 more to put together than a 350. They're so common now it seems hardly anyone builds up a 350 block without putting in a 3.75" stroke crank.
That engine cranks out TONS of torque with the small block 400 crank in it! I've got friends who've built 383's, and they love the torque & throttle response.Even though the longer stroke requires less RPM's, these guys aren't raving about any fuel economy gained with them. The best 383 stroker I know of is balanced, and backed up with a Muncie 4 speed in a 66 Chevelle. The Chevelle owner is running a 3:55 geared GM 12 bolt posi rear end, and loves the way it runs. My guess is the 350/350 with 3:08 gears would be the best combo for gas mileage. I hope this info is of some help to you.
I had a friend that had a real strong running 383 in High School. I would spring for the 383. He went high 12's on radials in a Regal in 1986. This was also his daily driver
Whoever sold the first 383 was a marketing genius. Why take a motor that has 400 inches and turn it into something that only has 383? The exterior of the block is the same. Put the same cam and other parts into a 400 and you will make the same power for less money.
I concur. why give away the cubes just to say you have a stroker. Build a 400 with the 5.7 or 6.0 rods and go .030 over for 406 c.i. You'll bury the next 383 you come across. Frank
Might be being slightly naive, but are there not cooling problems with the 400? Hence using the crank in a 350 to give you a torque monster but not a nice shiney kettle. If I am wrong I am sure someone will put me right. Is this a job for Super Squirrel...... P.
I built a 440 hp (engine dyno - not rear wheel) 383 stroker for my 56 Belair -- and I just love it -- lots of hp and the rear tires will smoke until I let off Let us know what you decide
Yea, the 400 had 'siamesed' cylinders and over bores dont make things any better. Its been done and will be agin I'm sure. I've never heard any one braggin about the fuel economy of a 400. The 350 thats in there does fine but the extra torque for towing and just moving the "big box" down the road would come in handy. Did I mention we have mountains out west?
Good points if you have a 400 to start with. But, nowdays, it's much harder to find a 400 block than it is a 350 block. If your 350 needs a new crank, or you can get a 400 crank cheap, the 383 is a great idea.
yes - 383 nice roller cam. If you have a 400 build a 406 - there are 400 recipes that put out over 500 HP and tq. Mine pushes my 3500 lb car to 13.01 times with tire spin. Hard to beat. Why not its free cubes. I guess a destroked 400 will attain higher RPM since its destroke. more torque = less strain probably better gas mileage but it will be what it is.
I have always wandered that myself.Why not just build the 400 .I always figured its like you said ,so people can say they have a stroker .Sounds better than saying i have a 400 i guess...
The 383 would be a big jump from the 350 and you wouldn't have to go buy an unknown block. I would suggest getting the engine kit from one of the suppliers though. A search for 383 stroker kit will bring up several good leads and the usual junk. This will keep you busy for a while http://www.google.com/search?hl=en&q=383+Stroker+kit&btnG=Google+Search On my 71 Daily Driver I am planning on using a 383 kit in the original block and then run a set of Vortec iron heads for a bit more zing. I had a 400 in my 77 1ton 4x and I will say that it did have the power even when it was tired. If you can get the 400 block and heads that might be the economical way to go.
Finding a good usable 400 block is the main problem, if you have one and overheat it you can bet the block cracked, I built a nice 383 for a friend, it's a bad ***.
Call me crazy but in the G20 you are better off with the 350 unless you want to drag it. But you talk economy and that will not happen with a 383 or 400. I say 350 in the van and hot rod the hot rod!
Wrong-o. The 350 after 1987 was a single piece rear main seal w/ roller cam. Adding a 3.75" stroke crank to a post-'87 block will give you a 383 w/ roller cam & the 1 piece rear main for, as state above, a little more than 200$ more than it would have cost to rebuild the 350 itself. (cost of stroker crank) The modern roller cam profiles you will be able to run w/ the roller block will more than make up for the lost 17 cubes. Retrofitting a roller cam into a 400 block is a lot more expensive than the 200$ it costs to add the 3.75" crank to the 350 block. Not to mention how hard it is to find a good 400 block. IMO, the 383 is the best dollar per horsepower SBC out there, which makes it one of the (if not the) best dollar per horsepower engine there ever was. Fuel mileage will not be adversely effected vs the 350. Things like cam, carburetion, and driving style will have a lot more effect on mpg's than displacement. A 305/350/383/400 will get similar mpg if they all use the same cam, heads, intake & carb... And the larger displacment motors will make more power & run more smoothly. (less cammy) for a given profile. And frankly going to a post 87 block w/ roller cam profile will give you several MPG in of itself.
I have built two 383's & they are torque monsters!! One I had in my heavy *** Chevelle with "doubble hump" heads ran 12.80's.
If you want MPG buy a honda. You want power screw the roller cam. Run a solid lifter cam,big intake. Then who cares what block it is. 400 inches is 400 inches. Stroker motors have so many thing wrong with them from an engineers standpoint. Or quit screwing around and build a long rod 327 or 302. Run some real rear end gears and away you go.
I did an inexpensive 383 for my 68 chevy pickup. I tried to do it as cheap as possible. I used a **** 9-103750 crank, 400 rods and MAHLE 599831 WR 30 pistons. The crank clears the pistons because it is relieved on the counterweights in the right places. I put 2.02 and 1.60 valves in the heads . The heads were 76 cc castings. I used a cam that was 216@.050 duration and put an 8150 stealth intake on it. This thing is a blast to drive.The torque is AWESOME! I can spin the tires at will. I got my foot to the floor all the time! If you were to use a small cam you could get decent mileage. My truck has a stock turbo 400 and 3.07 gears and 255 70 15 tires. JUST DO IT!
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