I hear about this all the time and i think i more or less understand what needs to be done to do this however if someone could explain what you have to do to transform your car into a 383 itd be much appreciated

 

Take a 350 apart and have it bored .030" over, then put a modified 400 crank (or an aftermarket 383 crank) into the bottom end, along with rods and pistons to accomodate the longer stroke. You also have to check and possibly modify clearances with the block and oilpan. Depending on the crank you may need a flywheel and harmonic damper to match an externally-balanced setup. It's a pretty involved process, and I wouldn't recommend trying it yourself unless you've built engines before.

 

well my car is getting stored for my lovely 6 months of winter so maybe ill get ambitious then. Is 383 the biggest you can go with a 350? whats the biggest possible size

 

396

 

so if someone is doing that extensive work why do people do a 383 instead of a 396?

 

396 costs more because of the larger stroke crank and shorter height pistons.

 

since you have to get the engine bored does this raise the chances of cracking the block? or should would it not make too much of a difference. I would love to do this when i have the money. Because why have a 350 when you can have bigger?

 

Depending on who does the work you can go as big as 454 SBC now. To do the 454 you would have to buy a Motown block as they have more meat. They use a 4.25 inch bore.
You can get a 406, 420,427, 434 and now a 454. Motown sells a complete 454 for like $10,000.00 that comes with a 2 year 24,000 mile warranty. It made 610HP and 575 lb of tq.
With that much power you would have to change your tran, converter, rear end and suspension. It would be a mean ride tho.

 

you know all you have to do is go to www.jegs.com and buy a kit and everything will match and work great

thats what i did

 

www.strokermotor.com

 

The block MUST be clearanced, it costs around $120-150 for a machine shop to clearance a block for a 383, the crank usually clears, its the rods that hit the pan rails. If you're using I-beam rods, you'll most likely need to go to a small base circle camshaft, if you're using H-beam's, most of them are profiled to clear the camshaft, it'll be close, but it'll usually clear (check it during assembly tho, its a nightmare to get ure hand up there but its possible), I think it was #3 and #7 or #5 rods that cut it close to the cam, but don't quote me on that, it's been a year since I last did a 383. I reccomend using 6.000" rods over 5.7" rods to get some better valve train geometry going. If you're going with a cast crank (stock 400 turned down to 350 mains, or an aftermarket external balance cast crank), you'll most likely need a balancer and flex plate/flywheel off a 400 block (or aftermarket 400 balancer/flex plate), if you're going with an aftermarket forged crank that is internally balanced, you should use a 350 balancer and flex plate.

Boring .030" over is fine, the maximum safe bore for a 350 is .060", you won't crack anything unless you do something wrong. As for going 396 - it doesnt yield enough performance gain to warrant doing so, cost vs. performance, you'd gain a lil torque, have a lower RPM band for the same cam, loose top end etc, 383 is a great compromise for a small block while still retaining good revving ability (mine goes 7500rpm without a problem). 383's are cheap and simple, there are kits available, but if you know what you're doing, sometimes its nicer to pick out your own parts. Jegs' have an eagle kit, but 5.7 rods and they are the lightweight SIR's or something like that, whereas I would personally build it with 6.000" H-Beam's if I'm putting any kind of real power through it - I spent $1500 on my rotating assembly right down to the balancing, file fit rings, bearings, flex plate and balancer, n it's good to 8000rpm and 1000hp.

 

396's are nice but area alot of trouble. Best thing to do is the 383, I did It's common, so alot of people can help you. Plus, you can't go wrong with the torque

 

that sounds really awesome. I dont have the coin for it now but hopefully during the winter while its stored i can get some work done on it. I have to start making my mind up now as to what order my next 4 mods come in, exhaust, sfc's, stroke it or a better stereo system. oh decisions decisions but regardless of what i pick it all turns out for the best =) thanx for all the useful info this has helped me get a good start on this

 

In regards to a 396 - in theory it makes more torque but you sacrifice top end horsepower - think of the crank as a wrench, use a really long wrench n the bolt comes loose easily n quickly (torque), but to take the whole bolt out, using a long wrench is a pain - using a short wrench (like a 327's 3.250" crank, its a pain to get the bolt started but once its loose you can get it turning really quickly which makes for great top end hp. If you build a 327 that goes 8,000 rpm, 650hp naturally aspirated is not that difficult to achieve - but you're making ****all bottom end torque, a 396 you'd have bucket loads of torque but you need some serious hardware to hold up at 8000rpm - so 383 is the in-between, it'll drop the power band around 500rpm in comparison to a 350 camshaft so you can go bigger on the cam to still rev to 5500 or whatever RPM range you're building it for, and have pretty decent revving ability.