Right now I got an LO3 in my car. Its leaking oil like crazy, who knows how many miles are on it, odometer only works when it wants to. Anyway, I also have a LG4 thats been just sitting around collecting rust. Its was in good shape last time it ran. I want to convert the LG4 to TBI. Will the LO3 distributor and intake manifold work on the LG4? What else will I need to do?
Thanks.

 

It should be a direct swap, except I would double check cam gear. LG4 was probably equipped with flat tappet cam shaft and LO3 may have roller (should be an easy check). You need to check that. The dizzy gear needs to be changed to accommodate camshaft type. Otherwise premature gear wear is likely with rather disastrous consequences.


//RF

 

The LG4 cam is almost identical in specs to the LO3 cam, just that it's a flat tappet.

Your TBI intake won't fit on early (85-down) LG4 heads becuase of the angle of the 2 center intake bolts (easily fixable, but not a direct bolt-on).

Also, LG4 heads are NOT swirl-port heads like your LO3. Just regular intake ports. So, that might throw the tune off a little even though everything else is very similar.

 

I think im going to put a better cam in it. Something else I just noticed, The heads arent 416's, The casting is 14022601. Those any good. Thanks

 

You've got a truck 305, not an f-body 305. 601s aren't bad heads with some work. I'm running worked-over 801s on my setup, which are similar. I think the 416s have better flow numbers, but I've heard people say the chamber design is better on the 601s/801s.

 

I figured it was a truck engine. I think I'm going to leave the heads alone. I figure there better than what I got now. Anyone now what kind of cam I should put in it?

 

Well, for what it's worth, the L03 is the better motor in several ways, and if all you're dealing with is oil leaks, it would probably be better just to fix them than to go through with a cam and motor swap. You'd be loosing out on a very fuel efficient (and torque friendly) head design, a hydrollic roller setup and obviously a better factory tune.

It kind of depends on what you're wanting to do with this thing. If you just want a basic mild stock-tune friendly setup, I'd honestly keep the L03 and maybe swap a little hotter cam in there and get headers, along with fixing the oil leaks. Of course, if the L03 has major problems with the rings or heads, you may be better to swap. But for all of it criticisms, the L03 is really a pretty tough and solid little motor and will usually run to 250K without many problems fairly easily. I had an L03 RS that I drove from 172k to 225k without any big problems, and my 1/4 times were as good as many 100k or less L03 cars.

But your cams are going to be cheaper with the older motor, and you're high performance options are better (cheaper heads, intake, etc). But then again, we are talking about a 305, so there's a little bit of a sacrifice in practicality in building one.

 

I thought about that too. Part of me wants a little more power. That LG4 I got is a strong engine for a 305. I was surprised when I first drove it, at first I thought it might be a 350. I've been wondering if someone put a cam in it at some time. It has a double roller timing chain, so it may have a cam too. But then again, I do like the gas mileage I get now. Who knows, its going to be a little while before I get to it any. Thanks