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I want to do a new motor and I'm not sure what to do. I have a 305 TBI now. I've heard good things about 383s off the line. I would assume a 400 would be similiar to a 383. I also heard that a 377 revs like nothing else, but that they are expensive and pretty exotic. Whatever I do I'll probably go to a carb and eventually a ram-air hood. I've got some time to figure out what I want, but I'm looking for info now. Anyone who has any of these motors I'd love to hear what you think. Even better would be someone that has had several. Also if you could suggest some books I could get to tide me over 'till spring when I can start on something. Also, if anyone has any hook-ups on parts I'd love to hear about it. I checked some prices for cranks to make a 383 and they were pretty high. Thanks in advance for the help.
Grab a copy of the October Chevy High Prerformance. they did a huge write up on a 383 vs 377 comparison. I still wonder why you would de-stroke a 400 though .
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Mark Lock
- 86 IROC-Z - My car, mods and ET's
- -= IROC Online =- - The site dedicated to the IROC-Z
Anyone know if CHP has a web site. I tried a search and all the addresses I could think of. I used to buy their magazines on and off, but can't find any of them.
go with the 383 or a 400, a 377 is just stupied in less your in to road racing. if you want gobs of low end torque got with a 383 or a 400. the 383 will more than likley be more to bild and you will need to notch out the 350 block for the 400 cranks. and you will have to modify your con rod bolts so they dont mash into the cam. i my self debated over building a 383 or a 400, i chose the 383 becuse it sounds more cool than saying "i got a 400". the reson for building a 377 is becaus you have a smaller stroke (3.48 vs 3.75) and the 400 block alows the heads to breath more easly by unshrouding the valves, there for you have a rev happy motor that can chug air. I've her od people puting a 302 crank in a 400 for road racing purpose.
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when the green flag drops the bull$hit stops
Each engine has its place. Different types of vehicles can benifit from each engine but not all will work. The 383 has the longer stroke than the 350 so it will produce more torque at around the same HP. The 400 will produce more HP than a 383 but around the same torque. The 377 becomes the oddball. This engine can be thought of as the bigger displacement version of the old 302. With the large bore of the 400 block and the shorter stroke of the 350 crank, this engine can produce high HP at a high rpm. These engines usually are built to redline at 7000-8000 rpm. I know of a T-altered dragster that uses a 377 with a 650cfm carb and runs high 9's.
87 IROC-Z Pro ET Bracket Race Car and knocking on the SuperPro ET class
383 stroker (carbed) with double hump cast iron heads and pump gas
Best results before the engine blew up
Best ET on a time slip: 11.857
Best corrected ET: 11.163
Best MPH on a time slip: 117.87
Best corrected MPH: 126.10
Best 60 foot: 1.662
Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
i my self debated over building a 383 or a 400, i chose the 383 becuse it sounds more cool than saying "i got a 400".
Hey Rube Goldberg,
Me, myself, I, and my own bad self just had a huge debate revolving around the issue of whether or not you graduated the seventh grade.
Forget the beastial butchery of the English language, how about that carnal wasting of every grammatical device known to man ?
Eh, check this out too home fries........
There's a helluva difference between "I got a 383" and "I built a 383".
Personally, "I built a 406" sounds best to me, although I think anybody who builds a motor based on what it "sounds like" probably just fell out of the idiot tree and smacked every dimwit branch on the way down.
And oh, I noticed you're pedaling a 350 these days.....did you puke the 383, or was this all just BS ?
There now, that ought to stir the pot a little. NYA AH AH.
did you see the chp that had the test of the 400s with Dart 200 and also 215 heads and a comp HYDRAULIC cam. Three tests made 440 to 450 hp and 498 to 509 ft/lbs of torque. No big gears or high stall needed.
My little old third gen with 3160 lbs of weight works pretty good with a 500 hp 400.
Yea, most people can't say
Quote:
I got a 400
because they don't want to go to the trouble of building one. And that's just fine with me.
PS. use some capscrew rods if you build a 400 with 5.7 rods.
[This message has been edited by jcb999 (edited September 27, 2000).]
I had the choice to do both a 406 or 383 buildup. I had a fresh 350 block and a fresh(never bored 400) sitting around.I did the 383 just because of personal prefference, but I like the idea of both. Destoking a 400 to a 377 is backwards in my opinion, unless you plan on doing some serious RPM pulling. I sold the 400 block, now sometimes I wished I would have at least kept it around, and did a 406 buildup just to have there when I wanted even more cubes.
You say the 383 cranks are $$, look at www.speedomotive.com and they have stoker kits that already have the crank done, rods ground for clearance,etc. Only place you'll have to be careful is on clearance for the cam. I couldn't install mine 4 degrees like I hoped for, but still pulls great straight up.
Good luck.......
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350 4 bolt main, Speed-O-Motive 383 stroker kit, re-sized rods ground for clearance,Hypereutectic pistons,9.8:1 compression,HPC Coated RPM intake, Speed Demon 750 cfm carb,World Products Sportsman II heads,2.02/1.60 valves, K-Motion springs, Comp Cam 1.6 roller rockers, Lunati adv.292/230@.050 with .512 lift,Crane pushrods,Proform HEI and MSD6A box,HPC coated 1 5/8 headers, 2.5" exhaust with 40 series mufflers,TH350 with B&M 3000 stall, Powertrax NoSlip Locker, 4.11 gears.
Destoking a 400 to a 377 is backwards in my opinion
Hmm, but de-boring a 400 is fine? That's what GM did with the 350, de-bored it to get a 305. And most of you say it sucks, but are building a larger version of it (respectfully). still
www.Competitionproducts.com in Oshkosh Wi.has the best prices on heads and internal parts,including stroker kits.Ask for Butch,he's an engine builder by night.
Thanks for all the help guys. I think I'm leaning toward a 400. Anyone have any suggestions on what to look for if I want to pull one from a junk yard? What cars, or trucks I guess, would have something suitable for a buildup/rebuild? Also, still haven't found october CHP. All the stores around here already have November in. Any suggestions? Thanks for all the help.
did any one tell you that your a peace of $hit. i still have the crumy 350 in the car right now, but the 383 build up will start this winter. i alredy have a 350 block(in the car) and my friend has a 400 crank i can pick up for cheap. a 383 sound more exotic. were i live i can only think of a small hand full of people with 383,and i feel i can get a little more repect with a 383 than a 350 or a 400, besindes when i think of a 400, i think of and old crusty $hity truck, with a crapy 2 barel that some hill billy is driving. us third genners need to quit fighting, over stupid issues like some ones wrighting ability.
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when the green flag drops the bull$hit stops
Originally posted by JEFJM: Anyone have any suggestions on what to look for if I want to pull one from a junk yard? What cars, or trucks I guess, would have something suitable for a buildup/rebuild?
They came in caprices and trucks in 69 through about 72 or 73 in some cases. Try and find a block that has only two freeze plugs and if that fails try to find a two bolt main.
Look at the front of the block where the cam hole is drilled. If the hole appears to be off-center in relation to the vertical area around the timing chain (the flat part right outside of the hole), that is an indication of core shift. If you have many to choose from, (not likely) choose the one that has the hole that is the least off center.
It's easier to find a 400 in trucks than it is in cars. Depending on the junkyard, you may have to search for one for a long time. GM stopped producing them quite a while ago and good cores are being snapped up. I found one in a 79 van.
All you want from it is a short block. Leave the intake (2 barrel), leave the heads (usually poor casting 882's). Make sure you grab the balencer and flexplate/flywheel unless you intend to buy good aftermarket ones. The 400 is externally balanced and you need them.
If you're building a 383 you can easily resell the block and make most of your money back. You only need the crank, balancer and flexplate for a 383. The 400 crank will need to be reground to fit in the 350 block. If you're building a 400 you can put whatever heads you want on the engine as long as you drill the steam holes in the new heads. Use a 400 head gasket and drill the 1/4" holes.
87 IROC-Z Pro ET Bracket Race Car and knocking on the SuperPro ET class
383 stroker (carbed) with double hump cast iron heads and pump gas
LS6 Big Block buildup now in progress
Best results before the engine blew up
Best ET on a time slip: 11.857
Best corrected ET: 11.163
Best MPH on a time slip: 117.87
Best corrected MPH: 126.10
Best 60 foot: 1.662
Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
.
That's what GM did with the 350, de-bored it to get a 305. And most of you say it sucks, but are building a larger version of it (respectfully). still 
