LT1SS

ok. so im thinking about building a 383 with a cast crank. good bearings. forged I beam rods, and hypereutectic pistons, 11:1 on a 4 bolt main. any ideas How much power i could push safely? what is a good cam for nitrous and stock heads with a 383?

96capricemgr

iTrader: (1)

You would be further ahead to keep the stock crank, stud the two bolt mains and put good pistons in it.

Displacement does NOT make power the topend does, the displacement does affect the rpm at which that power will occure more than it does peak output. The importance of this is overstated though because with the modest rpm capabilities of our pcm a well done 355 will have have the powerband moved high enough to really be a problem for street driving.
The $200 cast cranks are a step DOWN from stock too.

When you say stock headed I hope you mean stock castings with quality porting, otherwise the plan is a complete disaster.
The target compression is low too.

WS Sick

If you take a 350 and a 383 and set them side by side and everything up top is the same, they will produce PEAK numbers almost the same, but the 383 will peak sooner, if you only race dynos you stop there, but if you run your car on the street then you'll notice the 383s torque curve is much fatter across the rpm band where you use it.

Now add some good heads and a more suitable cam and the 383 makes much more useable power.

jarendt31

My 383 is similar to this one and I have absolutely loved it and Im pushing 380rwhp. The extra torque on the street is great and it will also allow you to run a slightly larger cam without any ill effects.

camaro-94-z28

iTrader: (3)

^but the money you spent on the extra cubes you probably could of made more power with a h/c combo. then just a cam. your set up is lacking alot of power running stock heads (looking at your sig)

WS Sick

Peak power yes, torque curve and down low, no.

But I would not build if you do not have plans of later at least doing some heads.

jarendt31

My heads had a mild port but my primary focus was to have a nice fat torque curve. I have over 350rwtq from 2800rpms upward and over 300rwtq from 2000rpms upward. High HP numbers are nice, but I built this car for primarily street use where torque to me is much more important. Plus my 380rwhp was put down on a mustang dyno which everything Ive heard are rather conservative. For the small amount of additional cost I'd reccomend a 383 over a stock cubes rebuild to anyone.

WS Sick

380 RWHP is very nice, especially with a fat torque curve, one thing to consider is how much longer the engine will last since it doesnt have to be spun to 6500 plus to make power.

jarendt31

Yeah I had a pretty quick Mustang with a 408 stroker, AFR 225s, huge cam, TFS-R intake and it was fast as hell, but I just got to the point the loss of low rpm drivability made it where I dreaded driving the car. It had decent torque but if I would have had a chance to do it all again I wouldve gone with AFR 205 heads and a cam in the .570 lift range with a lot less duration. Having 502rwhp was nice but I'll take an enjoyable car to drive over that anyday

BlackScreaminMachine

iTrader: (17)

383 is anything but budget, just buy a used one....

fergymoto

iTrader: (129)

Yeah good idea buy a used one for $1,500 and freshen it for $500. Good plan, that will run you the same or more than buying a brand new rotating assembly, machine work, and having it assembled by a professional.

jarendt31

The 383 can be done for pretty cheap, heck look at some of the places for a base 383 shortblock

WS Sick

Building the 383 shortblock is basicly the same as building a nice 350 shortblock with good parts. the extra cost is the clearancing, which can be done by yourself easily.