87 fuel injected engine

[gold84gmc]

i was going to put a fuel injected engine from an 87 into my 84.....how long or how hard is it to do this?

[VileZambonie]

Do you mean you are converting to TBI? Or You are just swapping the engine?

[gold84gmc]

i want to convert to TBI but if it cost too much/to hard of a job then im just gonna put money into the engine i have now

[truckdoctor]

Gold84GMC, You must be reading my mind. Or I'm reading yours? I am in the process right now of doing what you are talking about. My big thing is I have a complete 87 truck with a 305 fuel injected engine, so anything I need I just remove from the 87 and install it on the 84. (or so I thought it was going to be that easy)

I thought this wasn't going to be so bad because I am using the cab with the complete wiring harness for the 87 on my 84. I started by removing the intake, cleaning it up and getting it ready for the big swap to the 84 305. Once I was ready to go I positioned everything and immediately found out the center bolts only on the intake of the 87, they are drilled straight down into the head. At first I thought I was nuts, but I checked and found the head on the 84 engine are drilled at an angle, and the center bolts on the 87 are drilled straight down. This means the intake on the 87 doesn't just bolt up to the 84 heads without some reconfiguring of sorts.

I believe because I have the 87 block with good heads just sitting there I'm just going to install these heads and make the thing right. I can't see drilling the aluminum intake at an angle and having something go wrong or break something in the process. My concern now is I'm wondering if GM changed anything else in the process so that I can't put the 87 heads on the 84 block without something stupid going wrong? Like the liquid cooling holes in the block and heads not lining up and dumping coolant where it shouldn't be, or blocking something off and not getting coolent where it should go?

I will get this thing done, but unless you have all of the pieces it can get expensive on you real fast. Hopefully someone reads this and has done this before and knows a few secrets to help me out. So you see, we're both in the same spot in our trek to add fuel injection, I've just stepped a little deeper into the trek pile right now.

[Captkaos]

the only think that changed was the bolt angle.  Everything else is the same.  If it were mine, I would drill out the intake.  Pretty common practice.

[truckdoctor]

Thanks Chris, I wasn't sure people did this or not being this is the first time I've seen this situation. I believe I may take you up on your advice and do just that, it would certainly be a lot easier to do it that way than to replace the heads and adjust the valves.

I have done mechanical work, rebuilt engines, rear ends, and just about everything else, but I have never noticed anything like this before. Just goes to show you it doesn't matter how old someone is, you can always learn something new (even if it is on twenty four and twenty one year old engines).

Thanks for your help and suggestions. (again)

[Blue 82]

Not having a doner vehicle will make things a little tougher

A fuel tank with an internal fuel pump and associated fuel lines (supply and return lines from the throttle body to the tank) and harness/ relay

Make sure the block you use is knock sensor compatable..

A double roller timing chain is a no-no (the knock sensor may pick up the chain noise and retard the timing... An L98 Vette chain or LT1 or better yet an LT4 chain will work)

Cam choice is limited, realizing that a 350 TBI is not gonna make 450hp or even 350hp is a good start. Save that Solid Roller cam for some other project

You are gonna need some place to install an oxygen sensor

I'm sure others can add to the list

[Dragon]

Thanks Chris, I wasn't sure people did this or not being this is the first time I've seen this situation. I believe I may take you up on your advice and do just that, it would certainly be a lot easier to do it that way than to replace the heads and adjust the valves.

I have done mechanical work, rebuilt engines, rear ends, and just about everything else, but I have never noticed anything like this before. Just goes to show you it doesn't matter how old someone is, you can always learn something new (even if it is on twenty four and twenty one year old engines).

Thanks for your help and suggestions. (again)

If the heads from the '87 are in better condition than your '84's, then why not just go ahead and swap the heads, so you don't have to worry about mis-drilling the intake

[Captkaos]

87 vortec heads are pathetic in comparison to regular pre-87 heads.  They are great for stock TBI's, but they are very restrictive.
You definitely could swap the heads and bolt it on though.

All blocks are knock sensor compatible.