vanwyk4257

iTrader: (11)

I just bought a car with a forged 383 LT1 in it and supposedly it should be making 425+rwhp.

-4-bolt main '95 corvette block
-Callies forged 383 crank
-GM performance rods (LT4?)
-Forged 10.5:1 pistons
-heads and intake ported, 2.02/1.60 manley stainless valve in heads with competition valve grind.
-roughly .570 lift camshaft (don't have full specs in front of me)
-58mm BBK throttle body
-Granatelli MAF with a cold air intake setup and 1LE elbow.
-30lb injectors and PCM tuned by Doug Rippie Motorsports
-Edelbrock shorty headers & Y-pipe into Borla cat back (no cat though) with an electronic cutout.

What do you guys think, is 425rwhp a reasonable expectation with this combination?

I do have a pretty strong LT1 in my car right now with ported heads and intake, cam and bigger injectors, and it pulls very strong, so I'm excited to see what the 383 will do. I'm going to just sell the LT1 that's in my car now.

SpeedDensityZ

iTrader: (5)

It all depends on how the heads, cam, and intake matches. It is very possible with the right setup. Who done the heads? That will be what you need to answer that question.

StealthFormula

iTrader: (35)

6 Speed, Auto? Those Shorties are definetly not helping.

socal

iTrader: (1)

that sounds right, at the wheels. My 396 stage 3 lt1 heads,ect... made 450 to the wheels in a 6peed car when my friend had it

ABA383

iTrader: (1)

The compression is a bit on the low side...Without knowing exactly what was done to the heads and what the cam specs are its a crap shoot...If it was truely dyno tuned there should be documentation to go with it in the form of dyno sheets...I'm going to err on the side of caution and say that its probably a good bit short of that number...

--Alan

Z-RATED94

iTrader: (6)

Ditch the shorties for sure. You'll be choking the exhaust flow big time.

vanwyk4257

iTrader: (11)

The car it's in, and the one it's going into are both 6-speed cars. I have all the receipts for the engine build, but don't have full details on the head work aside from the items I specified above. I know the engine was built to make a lot of torque and not necessarily to be a 7000rpm high-revving powerband. It was built for exactly what I intend to use it for, track days and eventually wheel-to-wheel road racing. I know the builder/customer sent the specs to DRM on everything and had them tune the computer accordingly, so it wasn't dyno tuned. I know it's running a bit on the rich side right now, so I am assuming there are probably some gains to be made by dyno tuning it right? Can anyone recommend a couple good shops in Michigan/Indiana/Illinois that could do a dyno tune for me? Thanks!

96capricemgr

iTrader: (1)

Looks to me like a car built without any experiance to guide it. Just lots of names thrown at it.
I doubt it even comes close to 425rwhp.

The Vette block is not that great an idea, by the time 4-bolts are needed aftermarket caps should be as well so might as well start with a 2-bolt and splay it.
I can not imagine why someone would use LT4 rods in someting like this other than as a sales tactic to say it had something LT4.
That is basically stock compression, actually lower than the LT4 was, again screams this was done by someone without LT1 experiance.
The most powerful NA LT1s I can think of use smaller valves in GM casting heads, throwing "bigger is better" valves in LT1 heads is often another sign of a lack of experiance.
The Granattelli MAF and Edelbrock shorties are mistakes. I can not see that exhaust efficiently supporting anywhere near your hoped for power either.

Like I said looks like it was thrown together with names picked out of magazines not with real experiance as a guide. It may run well and pull hard but I for one think 425rwhp is extremely optomistic.

vanwyk4257

iTrader: (11)

Thanks for the input guys, perhaps what he meant to say was 425 crank horsepower instead of rwhp. I don't know for sure if it has LT4 rods, he just said GM performance rods, so I was guessing perhaps that they were LT1 rods. Either way I'm happy with it, it's a fresh engine with only 5000 miles on it and it has a canton racing oil pan already installed, so it will work fine for what I need. The price was right not matter what.

96capricemgr

iTrader: (1)

Buying a modded car gets you a lot of parts at a vastly cheaper price than you would pay new. BUT you can be buying someone else's headaches too, hope this works out for you.

mean94lt1

iTrader: (34)

agreed made this mistake too many times bought a sar was told it was a 383 only to find out when i pulled it apart it was a 358...but good luck with it!

vanwyk4257

iTrader: (11)

I know this one is what I was told, it's just that the seller was fuzzy on a couple details. I have no doubt about his honesty though.

StealthFormula

iTrader: (35)

I vote take it to the track and that will be the real test of its capabilities.