hey guys,

im looking for opinions backed up by results if you can of mods i can do to achice around 100 more hp and torque.(i am bias to adding more torque)

right now i am thinking:

-headers, with full three inch pipes, three inch in 3 inch out flowmaster rip off muffler
-some kind of chip upgrade
-new rod and rod hanger for my cc q-jet
-!smog a.i.r.
-heads of some kind or work my heads(wouldnt happen anytime soon, have heard stock heads are junk, if i can get 100 more power with out upgradeing heads i will)
-dual snorkel air cleaner assembly
-electric fan set up
-plugs and wires?what kind are acceptable
-my a/c belt is off and my smog pump belt are off
help me out with more sudgestions?

headers, what is the opinion of shorties with 1.5 inch primaries and 2.5 inch collectors, are these headers acceptable, they are headman, and like 70 bucks on ebay.

are there headers i can get that are long tube and require little adaptation other than piping?

 

Wrong answer about stock LG4 heads being junk. Larger 1.94" intake valves, porting work, upgraded valve springs, they'll be okay. I went with the World 305 heads, but they really need port work, too. My opinion is they make a better finished product, but they aren't necessary for your goals.

You left out cam. Your cam is a big HP culprit. Upgrade with a computer-compatible type.

Exhaust is the other. 1-1/2" primaries are probably too small. I like the Hookers. The entire exhaust system should be tossed and replaced with real stuff.

Your biggest problem is that year LG4 had low compression. That's going to hurt, no matter what else you do. But, at least the factory left the bar low enough so that your goal of increasing by 100 HP isn't too hard. I will not recommend, however, doing anything to increase the compression on your engine. There's a better option, which really finishes off the project.

I'm afraid I'll have to recommend getting rid of the 305 shortblock. Get a 350, go ahead and put your heads on it with the larger valves & porting. When done, you will have easily reached your goal, it'll do it with torque, and you won't even have to get an upgraded chip.

Follow the outline of the mods in my sig, you'll get +100 HP with your low compression 305. Do the same mods with a 350 shortblock, you'll more than double your current HP.

 

If you want a 100HP gain I'm thinking you will need new heads(or do up your own) and a cam swap.


Five7kkid- I have those heads too (world s/r)and am gonna port them. Any tips you can pass along that are specific to these heads?(i've read all the general guidlines and a couple head porting books but nothing specific to those heads). I heard the valve guide bosses are huge and can be slimmed down a lot, but how much can you do this before it compromises the structural integrity? ANy pictures?

How big is the cam you run with them? That is pretty impressive for a 305 and those low gears(at sea level). I have my heads on a 350 that runs 14.3s@96mph with a 50 state legal smog cam(203/212@.050) I was gonna buy new heads but from what I have heard these heads can perform pretty decently with a good port job.

PS- Do you have any tips about porting the valve seats while porting so you don't nick them, I don't want a $150 new valve job.

 

I just followed the Standard Abrasives Do-It-Yourself Guidelines, practicing on one cylinder of an 081 head.

I didn't remove any material from the World guides with regard to support length, just took off the "squared" end and smoothed it all out. I've seen articles about shaping the area beyond the guides leading into the bowl, but I don't know how critical that really is with a street engine. Same for around the spark plug in the chamber.

I didn't have anything to protect the seats while doing the bowls, I managed to avoid kissing them. That was my first porting job, too.

The cam is the largest flat-tappet computer-compatible Crane has. If I remember the specs off the top of my head, it's 218/236 @ .050, .464/.480 lift. I had it out to the track tonight along with the '57, needed someone to drive one of them back home. A fellow racer's wife volunteered; when we got home she said, "It's really easy to drive." The women in my family are afraid of it (afraid they'll "damage" it somehow).

Going to find out how emissions friendly it is real soon.