Installing a TBI system on an older 305?

[azdesert rat]

Howdy fellow Gear heads!.

I am trying to get my Mothers 89 Cap back on the road for her as cheaply and as easy as possable... She ran it out of water and ended up burning up two pistons.

It has a 305 -TBI 9.3 comp, code E.

I figure (Or I hope) that the cheapest, easiest thing to do would be to swap her the motor out of my wrecked '78 Cap. It has a recently rebuilt 1978 305 w/2bl carb.

Is it possible to drop in that old style 305 and only switch over the Ex Manifolds and the intake manifold with the TBI system?.

Or do I need to tell Mom to plan on riding her "Granny" bicycle to Church from now on?

Thanks for any help and/or Info you can give!.

[4onFloor]

you'll have to yank the heads off that 89 and put em on the 78 block in order for the manifold to bolt on. the 4 center manifold bolt angles are different on the 2 years. might have a problem with the exhaust manifolds too, the dipstick is on the driver's side on the 78 block and i think the 89 manifold will dump out right over the dipstick hole.

[azdesert rat]

Originally Posted by 4onFloor

might have a problem with the exhaust manifolds too, the dipstick is on the driver's side on the 78 block and i think the 89 manifold will dump out right over the dipstick hole.

Well, just like you were a 100% right about the bolt angles... Your right about the exhaust Man. covering the dipstick hole!.
That really sucks!... (Sorry, didn't mean you 4onfloor!) If it wasn't for the EGO and the air pump sys I could just use the 78 Ex mani. I don't know what I'm going to have to do take care of that.

If I put the 89 heads on the 78 do I use the 78's Rocker arms and push rods or ?


BTW, 4onfloor THANK YOU for the Quick and reliable info!. I really do appreciate the help!.

[4onFloor]

Originally Posted by azdesert rat

If I put the 89 heads on the 78 do I use the 78's Rocker arms and push rods or ?

rockers are the same on both years, and have have to use the 78's pushrods.
you can use your 78's exhaust manifolds and just get rid of the plumbing for the smog pump and just leave the smog pump itself in the font bracket so you dont have to get a shorter belt, but it's up to you on that one

[azdesert rat]

Originally Posted by 4onFloor:
you can use your 78's exhaust manifolds and just get rid of the plumbing for the smog pump and just leave the smog pump itself in the font bracket so you dont have to get a shorter belt, but it's up to you on that one

Well, that works just fine for me... but I didn't know what kind of affect it would have(if any) on the computer. With the 78's exhaust manifolds it also will do away with the O2 sensor.

The only reason I bring that up is because I have a 88 ranger W/ 2.3 EFI
and you can't fart in the cab without it having some kind of an affect on the system!.. or at least it seems that way!.

As you may have already guessed... I know even less about GM's ECM and TBI system than I know about fords EEC & EFI system.

Once again 4onfloor..... THANK YOU!.

[quaddriver]

couple a problems with using the 78 motor.

the intake/head bolt up problem as mentioned, the 78 is at least a full compression point lower (and hence makes less power), no hole in the 78 block for the knock sensor, you might need to drill/tap the 78 oil filter boss for the sender/pump relay. you can get around the dipstick/manifold problem if need be.

if she is faced with no car vs some money spent, locate a 88-95 350 from a truck and bolt that in, give her a little power to boot