ok guys I've been searching and and haven't found the answer I'm looking for and sorry If its been alreasdy asked but I'm thinking of swapping my 305 LO3 in my 90 RS and my question is can I just buy a 350 tpi and the harness that went with it and put in the 350 tpi fuel pump and just hook it up or am I wrong or missing somethings...It looks like I'll have to do this swap instead of a LTx/LSx swap those are too exspensive, but w.e. suggestions please and I do have to still pass emissions where I live if you suggest another swap.

thanks Tim

 

You'll also need the ECM (or at least the PROM), and little things like throttle cables (accelerator, TV, cruise), fuel lines, upper radiator hose, air inlet.

I believe a '90 RS has VATS and a VSS buffer box. VATS isn't a problem if your TPI also had VATS, but the VSS buffer box wasn't used for TPI, so there might be some rewiring there. Somebody like Pocket may be able to give you a better answer there.

 

You'll need to buy a complete 350 TPI setup in order to do this. You'll need the wiring harness, ECM, PROM, fuel pump, injectors, fuel rails, runners, plenum, intake manifold, throttle body, air ducting (if MAF car), MAF or MAP sensor, 350 knock sensor, and throttle cable bracket. I'm sure I'm missing other stuff. Its not as daunting as it sounds either. Besides moving the block itself the worst part is going to be swapping wiring harnesses. You have to remove the passenger side fender and pull the wiring out from under the passenger side of the dash and pull it through where it actually comes into the car. (Passenger side.) Then follow that up into the engine bay.

VATS is a potential problem but as I understand it you have a few options. The resistor bypass method is pretty simple and if you don't want to do that there is always reprogramming the PROM to essentially delete it from the memcal. There is also a VATS bypass module you can pick up from Hawk's for about $50.00.

 

I believe a '90 RS has VATS and a VSS buffer box. VATS isn't a problem if your TPI also had VATS, but the VSS buffer box wasn't used for TPI, so there might be some rewiring there. Somebody like Pocket may be able to give you a better answer there.

I have an LO3 which has tbi not tpi does that make a difference?

can I get the whole setup from hawks? I know the sell the engine with the harness but does it have everything I need t do the swap besides geeting a fuel pump and the bypass module or will I still need a few other things...and will the 350tpi work with my 700r4 trans?
thanks tim

 

I think you can get pretty much everything from Hawk's. At least that's what it says on their site. The 350TPI engine will bolt up to your 700R4 transmission with no problems. That's the same transmission that went with the 350TPI cars. As you said you'll still need a fuel bump and a VATS bypass module. Or you can bypass or eliminate VATS yourself.

 

So I could just get these things and I should be all set for the swap right?
http://www.hawksthirdgenparts.com/ca...accessory.aspx
http://www.hawksthirdgenparts.com/85...pumpkit-1.aspx
and for the bypass module is this what I need or is it something else?
http://www.hawksthirdgenparts.com/va...nversions.aspx
if I'm wrong can you send me a link for that part.
Thanks Tim

 

The LO3 has the VSS buffer box under the dash, so when switching to the TPI you'll need to run the VSS signal directly into the ECM, instead of into the buffer box first. As for the links you provided, it all looks in order.