before gettign to work on this i have been reading all sorts of stuff and i would like to clarify a few things with you guys. i have a 305 tpi 88 formula

i have heard that you have to replace the radiator, and that you do not, which is it? i was told i need to get an aftermarket computer for my fuel injection(tpi), and the wiring harness, if i get a holley stealth ram kit does that negate the problem? if i stick with the tpi set up, will it be able to flow enough to keep the motor happy?
i know some of this stuff has been covered but in my searching i have found and heard many conflicting stories, thanks to anyone that can help.

 

what exactly are you swapping? you say LT4 in your subject line but then you ask about stuff that has nothing to do with an LT4 swap. It will make things easier to get the new radiator, but you dont have to.

 

You'll need different rad hoses if you use a 3rd gen rad.

The only thing is that the LT1 is reverse flow so you may have trouble releasinging all the air from the rad.

 

no problem at all releasing the air. we spliced in the part of the 4th gen heater hose that has the air release screw on it, gets all of the air out of the system.

 

i am swapping an lt4 into my car, all to be said, i don't need help on the engine, i need help on getting it to work in my car. i don't want to sound like a dick becasue i am asking for someones expertise but my questions were straight forward. i want to put an lt4 motor in my car. the radiator question has been answered. thank you. the other question was about the injection system, can i keep the tpi setup from my 88 formula and put it on the lt4 (if so do i have to buy a new computer and wiring harness to run it), or if i wait (to save up some cash) and get the holley stealth ram kit will it get me around buying the new computer and harness? meaning does that kit come with the computer and harness that i would otherwise have to buy? i read what the kit includes but i don't know if i still would have to buy the extra computer and harness or not? i'm dumb i can't help that, but i am trying to get a little smarter day by day.

 

You can use your TPI altought I then don't see the point about installing a LT4. You'll get maybe 260-290 hp out of it max without mods.

One thing you could do it to run the TPI computer with the wiring harness on the LT4 intake manifold. which would be the same as the LT1 conversation on regular on TPI engine.


That being said you'll need to reprogram the PROM which would cost you as much as doing it properly.

you can get a used wiring harness and computer of ebay for maybe 200$.


Save you money and do it properly.

 

i am installing an lt4 for two reasons. the first is becasue i have a 305 and would like to get a 350 under the hood. the second is that i am getting the motor for 250, and am rebuilding it, so it will be modded, once it gets back together. i have to get a custom prom either way no matter how i do it so that having to pay for a chip is a null point. i would think my reasons for looking at the lt4 are about the same as yours for getting the lt1.

 

Still doesn't make any sense to use a TPI on that engine.

The runners are so longs, you'll have mad torque alright but very limited HP.

Right there with the tpi you'll loose more then 60hp.

 

the reason that i am thinking of using the tpi is due to money issues at the moment, if it would be cheap to manipulate the tpi into working well enough then i can do that for now, i am thinking about the holley stealth ram kit eventually. if it is going to cost an arm and a leg to get the tpi working then i will just get the motor built and when i get the money get an aftermarket injection kit. this goes back to an earlier question of mine. if i get an aftermarket kit, stealth ram, super ram or mini ram for example, will i still have to get a seperate computer and wiring harness or do kits like these come with what i would need? i could, and have looked at what comes in the kit but due to my ignorance it doesn't tell me anything.

 

Where abouts in wisconsin are you maybe I can help you. I live in New Berlin a suburb of Milwaukee.
Kory

 

i live in whitewater

 

lloyd, i forgot to tell you that you'll have to redrill the TPI instake manifold for it to match the LT4 heads . you will also need to block the thermostat housing.

 

like mat89RS said, if you want to keep TPI, it will be much easier and cheaper to just get a regular 350 and put your TPI on that. the amount of money you are going to spend on an LT4 just to rip off the intake and put your TPI on it does not make it worthwhile. I agree that you'll only get about 275 hp out of it. If you were to get a 350, you would have an outstanding engine for the same price that would produce more power and be a better combination of parts than an LT4 with TPI. If you indeed want an LT engine, I would suggest finding an LT1 complete with harness and all accessories and swap that in. right there is 275 hp, and it will be easier to get and cheaper than an LT4. Throw on some good headers and you are around 300. Then, later on, you can get your heads ported and polished, get a more radical cam, all that good stuff and make more power than the LT4. I'm seriously not trying to be a dick either, I'm just trying to save you some headaches later on down the road. but I'll go ahead and answer your questions as well in addition to mat89RS.

if you indeed put the TPI on the engine, then yes, your entire harness would be fine. You would remove the optispark and put a normal distributor on it, and everything else would be from the TPI system. as matt stated, you would need to redrill the middle intake holes for the LT4 heads, but it is only a slight elongation of the holes.

As far as I know, the Stealthrams and such use pretty much stock TPI hardware, so you could use your stock computer. You would probably want to get a chip burned for it though.

*ok, I just saw where you said you were getting the engine for $250. my mistake, I did not see that before. is it just the long block assembly that you are getting? Give us as much information as you can and we can help you all the more.

 

i'm not exactly sure i guess of what a long block assembley is, but if it means am i getting all of it then yes. it is the complete motor, the guy said it was out of a caprice, wasn't sure of the mileage, that is why i am gonna rebuild it. only difference between the vette lt4 and the others was the heads right?

so, i have to modify my radiator hoses a little bit and get a air release valve for to expel the air like it would on a 4th gen due to reverse flow cooling or whatever the lt engine does. i CAN use my entire tpi system without buying any new parts, i just have to fix the bolt pattern on the intake so that it bolts onto the new motor, but asap i should get an aftermarket setup in order to get full potential from motor. Air conditioning will either be deleted or moved. i need a new chip for the motor to work as well as it can. and my 5 spd should hold up through the break in period, but should be replaced before i really run it. i just want to make sure that all the information is being understood on my part.

:hail: you guys rule

 

fwi caprices never came with an lt4 they had the iron head lt1. If you have the whole engine with the intake ect. have the intake drilled for a rear mount destributor and use it. It is alot better than a stock tpi intake. You could still use the origional wiring.

 

thanks for the info kory, all i know is what he told me. i haven't gone and looked at it yet, i wanted to find out what kind of trouble i was getting into. either way if he told me incorrectly i am still going to use the same information to put the motor in the car. but thanks for the heads up.

 

ok, thats what was throwing me off, now it all makes sense. like Kory said, just get the intake drilled for a distributor and use all of your TPI gear.

 

So the TPI harness will work on the LT1 setup?

 

as what I said
except Kory tought about the LT4 & caprice ! ooooppps

 

oh, one more thing, I've a T-5 5 speed behind my LT4 conversion and I've put almost 50K very hard miles on it with hardly any problems. Only major thing I've done was replace the synchros and one of the gears when my clutch went out a while back and I had to drive it for a few weeks. It almost destroyed the tranny, but I was able to rebuild it and get a good clutch in it before I did any serious damage. You dont run into problems with the T-5 until you start running slicks, street tires dont really have enough traction to worry about problems.