questions for converting to TPI
 

Last summer I picked up a TPI set up off an 88 Z28 Camaro. My intention is to use it in my 69 GMC with my sb 350 and the T5 transmission already in use. Im new to the TPI and Fuel injection world so naturally I have many unanswered questions.
So basically I think I have everything to do the swap except for the PCM which was gone before I found the car.
http://img241.imageshack.us/img241/6715/p1080352lb0.jpg
http://img241.imageshack.us/img241/3996/p1080347qg2.jpg

The set up is off a 305 so Im guessing I need to find a 350 pcm. to make it work with my 350.

I pulled the whole under hood wire harness out of the engine bay all the way back to where the pcm was, I cut nothing. Im hoping that this is all im going to need as far as wiring is concerned but I have no idea what wires I need to keep and which ones to discard.

Im also aware that I must use a high pressure fuel pump and return line. what pump and tank to use is a huge question in my mind for I want to install the tank behind the rearend. I have a plastic foam filled 10 gal tank I would like to use but Im not sure if I can get a high pressure pump to use with it?
Im also thinking I will probably have to machine my heads to accommodate the fuel injector notch. correct me if Im wrong.

Ive also read a little something about different manifolds using different angle blot holes or missing a couple entirely. What should I expect to find when bolting the manifold onto early heads?

So as you can see I have quite a bit of work and questions ahead of me but Im guessing this is the best place to ask for help. any help is always greatly appreciated :)

Re: questions for converting to TPI
 

if you seach Tune port injection conversion or just Tuned port injection, it'll lead you to a thread that I started a few months back that will have all the info you should need. Also check out www.chevythunder.com. Lots of useful information on there.

Re: questions for converting to TPI
 

Great I'll check that out too.

Re: questions for converting to TPI
 

does it look like everything I need is here besides the pcm?

Re: questions for converting to TPI
 

You are def going to need 22lb injectors unless it is hopped up then you will need bigger than that. You prob want to give painless wiring a call about a harness too

Re: questions for converting to TPI
 

I'm at work, and will more detailed when I go home, but you will also need injectors, they are bigger for the 350, you can use the 305 PCM, it just has to be reflashed/reprogrammed. I will try to answer the rest of your questions after I get home.

Re: questions for converting to TPI
 

Please do the search and look for my old thread, everyone that I've spoken with about the harness swears that painless is horrible and they give other manufacturers that are supposed to be better. And he is correct about the injectors

Re: questions for converting to TPI
 

I ran a painless harness and it was plug and play. I really liked mine

Re: questions for converting to TPI
 

I bought this book. A lot of good info...

http://cgi.ebay.com/ebaymotors/TPI-H...Q5fAccessories

LockDoc

Re: questions for converting to TPI
 

buying that book. :) thanks!

Re: questions for converting to TPI
 

I just got done reading your thread. very good info. Cant wait to start researching some of those sites on there too. Im going to try and gather as much as I can as well as try and clarify some things on here.

Re: questions for converting to TPI
 

Sorry should have mentioned my engine combo. My 350 has a mild cam and flat top pistons.020 over. My heads are mid 70's big valve smogers (not the best I know). the engine is about 9.5 to 10 -1 compression. Im Using a Moroso windage tray, Im running the stock 11inch flywheel.
it has long headers and 2.5 inch exhaust. Rear end is soon to be a 4.56 ratio. right now its a 3.90. rear tires are 295 50 15's
Im going to be changing the cam to work with better with my combination. I have no idea what the specs are on it cause I lost the damn cam card, but I know its very mild, about 17hg's at 600 rpm
With my combo will I need more than 22lb injectors?

Re: questions for converting to TPI
 

I am curious, everyone that I've spoken with says you can't run an aggressive cam at all with a TPI. Have you heard something different? And if so please enlighten me.

Re: questions for converting to TPI
 

My buddy did on his 68 camaro with vortec heads and it is nasty

Re: questions for converting to TPI
 

mmm...you should tell me more...I'm already running the vortec 350. Can you get me all of his engine specs? And tune port specs as well?

Re: questions for converting to TPI
 

Ok so ive been hearing more and more about the use of vortec heads on older short blocks. Isnt there quite a bit of modifying that needs to be done to run these heads? Forgive me but Im uneducated about the years in which the heads changed can someone clarify this. Im also reading up on things and finding that some people are using LS1 intake system on the older styles. how similar are the blocks and heads form generation to generation. Maybe there is a informative web site someone cant point me too that explains this.

Re: questions for converting to TPI
 

Im guessing its because of the restrictive RPM curve people have been mentioning. Bigger cam = higher rpm power range.
I do have a book Ive been reading into a bit called Tpi swapers guide it has some info in it about installing bigger throttle bodys and bigger intake runners to get that higher Rpm Operating range, but Ive only glanced through that section.

Re: questions for converting to TPI
 

Horsepower: 330 hp @ 5,000 rpm
Torque: 380 ft/lbs @ 3500 rpm
Compression Ratio: 9.1 to 1
Block: Cast Iron 4-bolt, 4.000" Bore
Crankshaft: Cast Nodular, 3.480" Stroke
Heads, Chamber Size: Vortec Cast Iron, 64cc Chamber
Valves (I/E): 1.940"/1.500"
Camshaft, Lift (I/E): 0.435"/0.460" Hydraulic
Camshaft Duration @ 0.050" I/E: 212/222 degrees
Intake Manifold: Aluminum Dual Plane (Deluxe and Turn-key models only)

Re: questions for converting to TPI
 

Hope that helps

Re: questions for converting to TPI
 

He dynoed it at over 400hp. Not sure what rear wheel was but the tpi bigger throttle body, injectors and high flow runners bumped it from 330 to over 400

Re: questions for converting to TPI
 

he didn't use a roller block...see everytime I talk to someone about putting an after market cam in my truck it's above 485 lift. But otherwise I do believe I smell what you are stepping in. Did he have it dyno tuned as well? Or just a generic chip burned for it?

Re: questions for converting to TPI
 

one of my main concerns is the gas tank and fuel pump issue. I hear that baffles in the tank are necessary. what types of tanks work best for this conversion?

Re: questions for converting to TPI
 

He just sent his specs to street performance and they burned him a chip.

Re: questions for converting to TPI
 

They are only necessary if you have an in tank pump.

Re: questions for converting to TPI
 

awesome! then I can just use my aftermarket foam filled tank then :)