Today i took the intake and heads off of my engine to change the head gaskets, now im thinking about doing other things to my engine since most of the tops already off ... Is there anything i should do to improve my performance and horse power while this is off... I'd rather get it done now that the heads and intake are off.... i know about the weak spots of a 1984 LG4 but i dont know if i wnat to get into removing the cam because i dont want to really pull the engine unless im dropping in a 350, so anyone have any ideas on what i should put into the engine now that the heads are off??? thanx for any help...

 

You can change the cam with the engine in the car, but you will have to remove the radiator and A/C condenser, and there is a metal frame piece in front of the condenser which must come out but none of that is too hard. The only real downside is you gotta let all the freon out of your A/C system to get the condenser out.

 

Swap out the cam, you can pick up a LT1 cam for dirt. You could port the heads. New springs and 1.6 rockers would probably help too. Oh, replace the valve seals, they are prone to going and not much fun to change with the heads on. (plus they are only $20)

 

The cam is one of the really weak points of the LG4. The exhaust and air cleaner are two others. After that, heads, which you already have off. Finally, dished pistons on an '84, but let's stop there.

If you aren't willing to change the cam, then you are going to have to settle for mediocre performance until you drop in the 350.

Improving the exhaust will help no matter what, but the improvement will be limited without the cam change. Getting rid of the stock exhaust manifolds and y-pipe and putting in headers while the heads are off is an excellent idea. Put on a larger high-flow cat while you're at it.

I agree with getting your heads freshened up, at least those valve seals. Check the guides while you're at it. If you really want to help it out, get a porting kit and open up the bowls/ports a little while it's apart, even have 1.94" intake valves installed. If you do the cam change, get valve springs to match and put them on when you put the heads back together. Or, if you want to really go wild, pick up a set of World S/R Torquer 305's and put them on. Of course, they aren't the best economic choice if a 350 is in your near future, but they're the peaches for a good running 305.

You see, it's possible to really get into the "might as well" trap here. But, you're the one that opened up the can of worms...

 

I want to do the Cam switch...but ive only done a timing chain once and i messed up on that and It was only a 2.5 engine....:doh.. so i dont really know how to get into pulling a cam and putting a new one in without having my engine sit for a few weeks....but im gonna take your advice with the headers and heads...i have short funds so im gonna get my heads from the junk yard and recondition them....have any ideas on what car i should try and get some good 305 heads off of??? What type of headers would be best for the 84 LG4 engine??? What combo of cam and valve springs and lifters should i look for??? thanx for any advice. I just had my 17th bday and im planning on turning this car into something to brag about and im doing all the work mostly on my own so im kinda proud of my self....

 

The cam swap does take a little bit of touch, but it isn't any harder than the heads. It's covered in all the popular service manuals (Haynes, Chiltons, etc.).

Take a look at the casting number on your heads: Does it end in "416"? If so, those are the best factory 305 heads to work with. If not, I have a set sitting in my garage that need a home, I just didn't have the heart to throw them away. You can have them for shipping costs (~$75 UPS).

I am really impressed with my Crane cam. It's a little on the big side, so a 2030 or 2040 might be a better choice. The computer doesn't complain about it, though. The springs they recommend to use is on the cam card, but I don't have it with me right now.

I assume you don't have to worry about emissions, so the non-A.I.R. Hedman shorties w/y-pipe, 3" cat would be a good way to go. You'll need an O2 fitting to keep the CC carb & distributor happy, but that's not too big of a deal.

Don't know if you noticed, but the '57 in my sig was my 1st car. Got it a couple of weeks before I turned 17, had been run into the back of a pickup. Had all the front sheetmetal off, did a ring and valve job on the engine while the front end was off, drove it for the first time about a month after my 17th birthday (that was 30 years and a couple of months ago). There's nothing like being able to say "It's my first car", and "I do the work on it myself".

 

Thanx for the advice...would you really let me get the heads...that would help me out a lot if you could...i think im gonna try and get a new cam in too im thinking i might as well while everythings already off...and ive got a haynes manual so it should be able to take me through it...there arent any emissions laws in mn well thats what my mom has told me...should i remove my cat? or get high flow ones? sorry for all the questions, i just want to get some performance into my engine... thanx for any help...

 

You can change the cam with the engine in the car easily. You don't even have to empty the A/C system of freon. When you unbolt the compressor from the engine (I guess you already did that?) don't unhook any of the A/C lines, just push the compressor over toward the fender and wire it over there out of the way. Then instead of totally removing the condensor just get it loose and have someone lift it up out of the way and hold it while you slide the old cam out and the new one in. There is also a X-brace right in front of the condensor that you have to loosen/move as well. No biggie at all.

Summit sells a good cam for like $150ish or something I think. Almost identical to the cam I put in my 305. It's around 204/214 @.050 with .420/442 lift. Several brands sell cams that are almost identical to those specs, pick up the cheapest you can find including new lifters in the kit. You'll pick up 25-30 hp with that cam easy, swap over to a Performer intake while you're at it too (or the comparable Weiand intake). Should be like a new car once you get it all back together with a good exhaust... You can make 240-250hp easily with the LG4 with a good cam/intake/exhaust... Check out this article I scanned up on my site, a LG4 buildup. www.inter-scape.com/ray/305buildup.htm They made 269hp with the stock heads, but they used a little bit hotter cam and intake than you'll want to. You can certainly come close to their numbers though, especially if you port the stock heads some while they're off...

BTW, before you pay the shipping on those heads make sure you don't already have those 416 casting heads. I was thinking LG4s already had those...

 

I was serious about the heads. But, check the casting numbers on yours first - no need to pay shipping if you've already got the same thing.

Keeping or eliminating the cat is a toss-up. You can get all the aftermarket parts needed to replace the exhaust from heads to rear bumper, and you can install it all yourself with standard hand tools. Eliminate the cat - well, technically it's not legal, even if you don't have inspections, but will also probably require some kind of shop assistance to install (unless you have cutting and welding equipment available for your use).

 

I've got those heads but my dad says that i need different ones because they are blown or something like that so could i still get them??? should i change the springs on the heads if i change the cam???

 

Unless they are cracked, they are rebuildable. Mine I know need guide help (either knurled or replaced), and a valve grind job.

New springs would be a very good idea.

Email me if you want to discuss it more.

 

Kevin,

5-7 is right (as usual).

If you already have "416" heads, all you'll need to do is rework those. Usually, a machine shop will hot tank and Magnaflux your heads for a minimal cost. If everything checks out, use what you have.

The "416"s respond well to bowl enlargement and larger (1.94") valves, plus some short-side radius grinding and port matching. The valve enlargement and bowl work are generally done at the same time on the same setup, so the cost is not excessive for both. Bowl porting the exhaust side will really pay off as well.

And your stock exhuast system is really restrictive. The manifolds themselves are a big reason on the LG4. A high flow cat is easiest to install, and provides almost no restriction.

And Ward is correct - you don't need to remove the A/C condenser, just move it out of the way while still connected so the cam can be removed and installed, a little like this:

 

I am working a set of "081"s which are the centerbolt brother of the "416"s and am interested in the larger intake valve. How would the Manleys with the necked down stem work in this situation. Or.....any other suggestions

Thanks

Darrell

 

After sleeping on it how much of a gain would changing to a 1.94 intake give?

And.....are the necked down stem valves worth the extra cash over the standard ones?

Any thoughts.....

 

Oh and I forgot....I have a set of standard valves in a set of "416"s that I have worked that I had a backcut done on them. Would this be a decent gain for cheap since I already have them.

Just need to relap them to the different head?