I have a 97 vortec 350 block that i would like to build for my 86 iroc. Im planning on putting a newer style roots supercharger on it to get the power i want. the question i have is should i build this block or buy a ls1 and build it? For what a ls1 cost i could have most of the parts for the 350 shortblock. Im thinking it would be more cost efective to build the 350 sence im goint a compleat rebuild anyway. The other thing is can i use my current wirring harness or buy a new stand alone ecm, what about just changing the stock ecm? the supercharger is going to be a wipple or kenne bell

Thanks

 

stick with the old school 350, because anything over 450 hp tends to smoke 700r4's so you will probably need the extra money for a well built tranny.

 

At this point in time the 350 may be more sensible, but you will be essentially maxing it out. I would go with the LS1 because when all is said and done youll be making comparable numbers, but youll be able to further expand with the LS1.

Oh and either way he goes with this setup, hes gonna end up trashing his tranny. That supercharged setup will make around or over 450 depending on what else is on the car. Just make sure you take into consideration the strength of the rotating assembly and your drivetrain (this includes the rear)

 

another thing to consider: weight between them. I don't know how much a 350 weighs, but an ellis juan weighs about 20lbs more than a 3800 II. same/more power going w/less weight to push around is a win/win combo.

I've also heard good things on using a 5.3 short block out of a truck w/ls1 heads.

 

if you have the money do the ls1, ull have better gas mielage and driveablity, most bolt on ls1's with a procharger can top 500 RWHP, throw a blower cam in there and ur going for 550 rwhp, and if you buy the ls1 with a t-56 it will actaully be able to handle the power with a good clutch

 

I just finished talking with my engine builder( this guy build some of the best circle track/ drag racing engines around. He was best dirt late model engine builder 99-04) and he recommended that I go with the 350. Only because parts are a lot cheaper o and I’m building a 383 out of this block. He is telling me that with all the lightweight components im going to be using for the internals and what porting/polishing to be done I will be some were between 400-500hp to the wheels without the supercharger. He also said to use my current iron vortec heads because of the amount of boost ill be running I will go through head gaskets like crazy. Hopefully I can get a 50% increase in power with the charger that would make my Hp/Torque where I want them to be.

thx

 

Just make sure you go with something like copper gaskets. Spend the big bucks up front on something like that because you dont wanna be constantly taking your heads off to fix a gasket.

 

the only bad thing about this is im going to have to stay with the tpi setup untill i get the charger. All i need is the vortec baseplate and high flow runners. atleast ill be able to get the engine hp numbers before i put on the charger.