im switching out my burned out 305 for a 350 but im keeping the same tpi setup/computer. will i have any problems? i mean the computer wont know the difference right?

 

Are you upgrading injectors? If not you will be running lean.

Are you swapping knock sensors? They are different between 305 and 350s.

I'd recommend getting a new memcal (the thing that plugs into the ECM) from your local dealer, call them up and explain the swap and they should be able to get you a new memcal.

 

you need a new memcal (chip) as said, also new injectors as said. I got a set of vette injectors (the ones you need, 22 lb/hr)for sale----- $120 let me know if ya want em

 

yeah they hit on the button..

the computer needs to know the different from a 305 and 350.. so you need the chip, or just a 350 computer..

and definitely you need 350 injectors...
also the knock sensor is different....

 

Is your vehicle MAF or Speed density. This is the main question. The only difference in some models (90-93 F body)305 or 350 are the injectors.

 

yeah i was planning on new injectors. but how much is the part that plugs into the computer? im fast running out of money so would it at least drive if i didnt change it all out right away?

 

What year model is your vehicle?

 

its an 85 irco-z. i think the code is LB9

 

If it's an 85, it's MAF. If it's a mild engine, don't change a thing. Don't buy injectors. Don't put in a 350 chip.

MAF absolutely does not care what engine is behind it. It just needs to know what size the injectors are. It measures airflow, and injects fuel to match. If it doesn't know the injector size, then it thinks it's injecting a different amount of fuel than it has.

If you do want to change injectors than you absolutely have to change chips. But if you're on a tight budget as you claim, you do not *need* to change anything.

 

but the car will not run to it's fullest
I'd say if you can do it DO IT (chip and ingectors)
biker

 

The thing is, the 85 ECM is basically junk. So if you want to get into PROM burning, you might as well swap ECMs. Sounds like this guy is a relative novice and is just trying to stay on the road with the new engine for now without breaking the bank. We've all been there.
I'm quite aware of the benefits of PROM burning though. Been doing it for a while.

 

ok so i can keep my setup now but it wont get 100% power. what exactally is prom burning and how do i do it?

 

I just finished the swap. At first I just dropped in a 350 short block I'd built. It was a all new roller cam motor and I was disapointed. Thats when I started hunting and found this site. There are a lotta stuff you can do that really don't cost a whole lot but you need to do research and have some mechanical ability. If you want to spend the time here are the tips I have to offer. I rebuilt mine again in lss than 100 miles.. This long *** post is just a few...

Number one deal is to make sure that you know what block and heads you want and need to run to keep the right flywheel combo. Think of where and how you'll use the car and what would be the best for you.

Then consider this goal. Moving as much air, air- fuel and exhaust as effecently as possible in as large amounts as possible as unrestricted as possible.

Free or cheap Horsepower..

Adjustable fuel pressure regulator : I made my own, I took the cap off the top and made it more concaved actually moulding the lid outward slightly. Then I drilled a hole in the center and welded a 6mm nut (10 mm head size ) installed a small bolt that would clear the plentum and put it back together, I found it ness to silicone a washer smaller than the bolt threads on top of the spring on the inside of the reg.. Worked perfect and Raising the fuel pressure to about 48 at idle and 53 on hard acell on the 5.0 injectors seemed to work fine in my case. Cost me nothing. if you had someone else weld the bolt on it would still be cheap.

Port the heads. Cost some money here in cutters, griders ext... I actually changed to early heads which you should have anyway. Find out what diflection is and eleminate it as best as you can for a free flow of air and exhaust..

Now that you have the port tools.. Find madmax's post on porting the intake, plentum and runners. and do those too. Try to fit headers into the budget.

Cam, chose one that works for your ability. You don't need a cam that pulls to 7 grand if you'll never see it. I am running the same cam as the ramjet motor runs. It was cheap and works good for me. Then I added new roller lifters picked up on ebay and 1.6 rockers from Summit. It works pretty well.
I know I don't have the fastest car out here but my 90 formula came with the factory dual exhaust 5 speed ect and it was pretty fast for a stock 305. The first time through with the new 350 I was not happy and I had the same cam less the roller rockers.

Buy books and read.. study and print stuff of of here.. Take your time..

* Ported and Polished Early style Cast Iron Cylinder Heads and Manley 2.02 and 1.60 Pro-Flo Valves.
* A Ram-Jet G.M.P.P. Roller Cam with 1.6 Harland Sharp Roller Rockers.
* Homemade Adjustable Fuel Pressure Regulator.
* Simease Ported Plentum.
* The Intake is modified to fit the heads then Ported and Polished as in the thread from MadMax.
* The Runners are semi Simeased and all Gaskets Matching.
* A 52MM Holley Throttle Body.
* The Balanced Rotating Assy has 1.25 Dome Forged Pistons, CR = 10.4 - 1.
* Edlebrock Chrome T.E.S. Headers.
* Twin High Flow 3" Cats with 3" Exhaust tubing Replicating the Original Factory Dual Exhaust.
* Flowmaster Cat Back System.

 

all good information. thanks a lot. anything i need to do to my computer? chips or etc?