tamatt27

I've got an LT1 outta 9C1. I have the computer, but no harness. I'm curious to know.....cost and HP-wise...is a 383 rotating assembly for the LT1 worth it? I will need to keep this car streetable..since I will be driving it back and forth to work and school. A/C will be retained. I'm thinking of some 190cc AFR heads..that's about all I'm sure about. So, what I'm really asking...would a 350 LT1 make 400 HP and still be streetable, or would a 383 LT1 be the better route? I'll be using my 700R4, but I'm thinking of a T56 swap later on.

ShiftyCapone

iTrader: (7)

A 400hp LT1 is very streetable and can be easily achieved with the LT4 hot cam hit. You would want to port the heads a bit to get even more power but you can have almost 450 HP in an LT1 and LS1 and still be streetable with only a mild lope. *** bless multi port.

tamatt27

So I was thinking.....The LT4 Hotcam Kit includes: the LT4 Hotcam, rockers, valve springs, valve caps,valve keys,and valve spring shims, all for $509. How would a pair of 190cc AFR LT4 street heads, an LT4 hotcam, and an LT4 manifold perform? I noticed that the AFR LT1 heads are the same price as the LT4 heads....$1750. How much HP do you guys think that would make?
And just for ****s and giggles...how much HP do you think that setup+a 383 rotating assembly would make?

TKOPerformance

A 383 should be worth about 20HP and 40 lbs/ft over a 350. I ran a lot of different engine combinations through a computer program when I was building the engine for my truck, and I was having the same debate. At the time it wasn't worth it to me, because 383 assemblies were still a bit on the pricey side. The parts have come down a lot in price since them.

The 383 is king of the street though, because it is a torque monster, and that's what makes a car fast on the street, where part throttle acceleration is very important.

The 350 will still shred your tires though, especailly with the HOT cam kit and AFR heads. The 350 would probably be a better choice for a car with a T56, because the short runner LT4 manifold makes most of its power up top, which is more conducive to a manual trans. The 350 will have a lumpier idle compared to a 383 though, because the LT4 cam is about as big as you would want to go for a street cam in a 350. It's a nice aggrsssive grind for a 383 too, but the extra cubes help smooth out the idle.

I would say that the LT4/AFR/350 combo would make around 420HP and 400 lbs/ft. The LT4/AFR/383 combo would be good for about 440HP and 440 lbs/ft. Those are fairly conservative numbers that you should see with no problem.

camarobeast84

iTrader: (1)

Hello, I'm currentley in the same position as the original poster, ready to build my 95 lt1 and need to decide wheather or not to stroke it to a 383 or just build the 350.

I'd like to hear from as many people with EXPERIENCE as possible from both the 350 and the 383 standpoint.

I'm not looking for any more than 450hp MAX, close to 400hp at the LEAST.

Which one would give the better driveability on the street for joy rides or rode trips?
Which would be more dependable and have the most longevity?
Which would have the better fuel economy?

Please post as much info as possible including personal results for certain combos, costs for certain setups etc...

I'd like to have a good idea of how much I'll be spending for both setups, and what to expect.

Thanks, and for the love of God, please as many people post as possible!

Klortho

Ported heads (ported as far as they can go) and intake, bigger cam (XFI series or CC306, but the XFI more than the 306) would probably put you close to 400 hp

as far as costs.....it all depends on where you buy the parts and who ports the heads, I've heard of stock LT1 heads flowing well over 300 when ported correctly.

camarobeast84

iTrader: (1)

I'm thinking about using Advanced Induction for the heads, cam , etc...