The thing I am going to urge to you the most is that you buy a parts camaro / firebird that has been totalled, or has a rod knock or something. No ebay setup is truely complete, and you'll find yourself nickle and dimed to death trying to get all the little parts and peices it didn't come with.
As far as the physical setup goes, the 86 is the best year of TPI goes in your case, if you want to run a MAF. Avoid the 85 setups like the plauge, it can be identified by the piggy back MAF burnoff module. It is very prone to failure, and is over all an inferior model. 87-89 setups are still MAF, but the physical intake will need to have the bolt holes modified, and you will need a small cap HEI with the remote coil. Some later setups also had the cold start injector removed, having the cold start enrichment programmed into the ECM.
If you wish to run Speed Density, you need a 90-92 setup. They will need the small cap HEI, and will need to have the intake modified to fit your old style heads (bolt holes, can be done with a die grinder)
Now, there are a couple different things that can help you decide wether to run Speed Density, or MAF. Both have their pros and cons. Speed desnity is an overall more efficient setup, as it is newer technology, and it does not have the expensive MAF. MAFs do not like a rough ride, or any sort of dirty air. They have a very small filament that can broken if the setup is jarred really hard. Also, the MAF is a major bottle neck, it does not flow very well, and just goes to lower just how high you will be able to get your engine to rev up. On the other hand, the speed density setups will not take any sort of engine modifications without a new chip. So, if you don't plan to take her off-road and beat on her a bunch / running a more radical engine, then go MAF, otherwise, go speed desnity. If you are running a larger displacement engine such as a 383 or 400, go speed density.
As far as stuff you need to install into your truck to accomodate the new EFI system, there isn't a whole lot to do.
First off, you'll need to buy a TPI in-tank fuel pump, put it into an 87+ Blazer tank, and install it in your K5, This immediately takes care of the fuel pump issue. You'll need to replace all of the rubber lines with high pressure fuel injection line. The steel braided lines from the 87+ trucks with TBI is awesome for this
The TPI pump is a direct bolt in replacement to the TBI pump that'll be in the EFI blazer tank.
Next, you'll need to install a VSS. The easiest way to do this is to put a 85 mph speedometer with the green sensor on the back on. You can feed the signal it puts out directly into the MAF ECMs. If you don't want an 85 mph speedo, or something, you can buy a VSS that goes inbetween the transmission and speedometer cable, in either the 2 pulse per mile that MAF systems need, or 4 pulse per mile the later speed density systems need.
Finally, you'll need an 02 sensor installed into the exhaust you are running. With manifolds, you'll need to take them to someone who can weld on cast iron, or you are pretty much guranteed to crack your manifolds, with headers, you'll need to install the bung into one of the collectors, and depending on how hot your engine runs, you may need to get a heated 02 sensor.
You also need to make sure that you get the setup that you need for your truck. Aka, get a 305 setup for a 305 / 327, and a 350 setup for a 350 / 400. TPI is a fantastic system as far as the electronics go, its the actual physical intake that turns most people off from this system. It'll only flow well enough to get a 350 revved up to about 4800 rpm. There are a bunch of expensive aftermarket parts you can buy to replace the stock intake with, and get the setup to flow for 500 horses if you want, but the cheapest option is to install an LT1 intake. You can get them off ebay for less than 200 us, and then ship them to the guy at
www.lt1intake.com to get it machined for your block / get the chip you need burnt etc. The other thing that you need to look at is the injectors. they are 19 lb/hr for the 305 setups, and 22 lb/hr for the 350 setups. If you are running a higher horsepower setup, you need more fuel to go along with the air. You can buy aftermarket injectors for your setup. Ford, and Chevy both used basically the same injectors, but Ford ran ones with a higher flow rating, some as high as 30 lb/hr. The stock 5.7 LT1 intake would have 24 lb/hr injectors in it.
For any information you could possibly need about TPI, check out
www.chevythunder.com -- Its very indepth, and covers absolutely everything you need to know about installing TPI into other vehicles / the way TPI works, and other specs
