I have a 89 K5 Blazer with a 350tbi in it and I really can't decide on what to do for either building or swapping the motor. It is not a daily driver and it will see a fair amount of time off-road.

I have about decided on buying the 330hp gm crate motor and putting nitrous on it, probably a 100 shot. Does this sound resonable?

I know that I will need to do something with my tbi (either BB tbi or holley tbi etc.), an intake, burn a chip and probably a fuel pump. What else will I need?

Right know the only mods that I have done are, K&N, injector spacer, the cone shaped thing that goes on the bottom of the air filter housing, headers, open exhaust, vacuum adjustable fuel pressure regulator, and a three wire O2 sensor.

What else will I need to do to get the crate motor to run?

Or would it be better to go with a different setup? I have thought about MPFI but I don't think that it is necessary for the horsepower levels that I plan on running. Am I wrong?

Also I believe that the motor will hold up fine to a 100 shot, what do yall think?

Thanks,

Trey

 

Lets pretend that this motor is going into an f-body so that we can keep this disscussion legal You will need a vortec manifold to work with that motor because you stock intake is not compatable with vortec heads. How many miles does your current motor have on it? You may just be able to upgrade to vortec heads, add a cam of your choice and have basically the same motor for half the cost. Other that the intake everything you currently have now will transfer over. You will need chip work to make the most of any heads and cam swap that is not stock. (heres a hint to search for chip burning) You should be able to re-use your stock 350 injectors but a 2" TBI unit would be a good idea.

By the way, welcome to the boards.

 

I am not in a real hurry to drop a motor in it. The "car" has 180,000 miles on it. I have had it for about the last 6,000 miles. When I bought it, I was told that it had a rebuilt or new motor about 30,000 or 40,000 thousand ago and I believe it to be true.

I want to spray it now, and I will probably stay with this motor till it blows, whenever that it.

My main concern is if I plan on putting the 330hp motor in, I figure that I need a throttle body with a 2" bore, either a BB tbi or a Holley, but if I put nitrous on it now I need a plate for a sb tbi. So I could buy a plate for a BB later or I could buy the BB nitrous system and a BB tbi or Holley now.

I don't really want to spend that money now, if yall recommend that I go to a different injection system such as multi-port. Which I am not opposed to if that is what it takes.

So I am really concerned as to whether the TBI will be a sufficient system for the 330 hp motor.

Thanks

 

I dont understand, you want to get a crate engine?
Why not rebuild your current motor. If this isnt a daily driver, I am ASSuming you can afford the down time required a rebuild. That way you can get what compression you want, your choice of pistons (forged or hyper), your choice of cam ( i think the cam in the GMPP 330 is lame), and you get to decide whether u want vortec heads and the associative manifold. You already have the block and crank.

 

I agree and may have overlooked this a bit from my firts response. Many people run the GM 330 with a 2" TBI and have great success. If you plan on spraying large shots I would rebuild what you have and prep it accordingly.

 

I considered that. I considered building a 427 carb motor. I have considered all kinds of things. But it came down to that I think that the 330hp motor and a 100 shot would be adequate for me and crate motors are simple and reliable.

I have rebuilt many motors, but by the time that I find a 4 bolt block (which I want although it may not be necessary), and get the machining done to it and buy heads and a cam and either buy a complete new rotating assembly or just buy pistons and have crank ground etc., and bearings and gaskets and oil pump etc. it seems a lot easier and not a whole lot more expensive just to buy a crate motor that will provide me with my power wants.

Also I don't want a real big cam because my "car" sees a lot of off-road time and bottom end torque is needed. So given all of this the 330 hp motor seemed to fit the bill.

What is the most feasible hp that can be had on a TBI, I would just as soon build a motor up to that limit and get the rest of my horsepower from the nitrous.

Now I am considering building a forged motor similar to the 330 hp crate motor so I can spray it more, although I really know that I don't need any more hp, I just want it.

Thanks for the advise. Anybody have any other thoughts on this?

 

With the right tuning combined with a 2" TBI unit, you can be right at that 330 hp mark. You may want to send JPrevost a PM. He is running exactly what you want and can shed more light on his personal thoughts on the combo. Any TBI set-up that you choose will all boil down to chip tuning. You will really need to consider this or 300 hp will not be achievable with your stock or any off the shelf tune.

 

i want to do the EXACT same thing u do.

http://www.jegs.com/cgi-bin/ncommerc...01&prmenbr=361

that manifold will fit a TBI to vortec heads.


then next year i want to rebuild it for nitrous a 100-150 shot

http://www.jegs.com/cgi-bin/ncommerc...88&prmenbr=361

theres a Holley N.O.S. system.

I wouldnt run nitrous on the motor the way it is (i want to rebuild it with right pistons,rings, cam made for nitrous, and colder plugs.)

but if little stock 4 cyls with colder plugs and adv. timing run 50-75 shots im sure a 350 could run a 100 safely

i have no idea about chips or any of that thou its confusing

 

I will either learn to burn chips or if I don't want to take the time I know someone who can, so that it not a problem. I don't know how yall feel but I feel that a small block can handle a 100 shot easy based on my experience and others advise.