My 79 L48 won't break loose even with cat off, carb rejet, advance and curve adjust. But under he right conditions I can get a chirp out of second

 

My 78 SA has been super tuned and is stock with no cat and performance mufflers etc and will not even get close to BT....I don't know of any stock 78/L-48's in my club that can BT....

mk's78

Mike

 

Sure. The stock L48 bottom end is built well enough to handle just about any naturally aspirated top end that is streetable (Take that with a grain of salt). Not sure if yours is rebuilt, but if it is, they likely used flat top pistons. I digress. The MAJOR power robbing components in the L48 are the heads and cam. The exhaust manifolds are somewhat restrictive as well, but I'm reserved on calling them a MAJOR restriction. However, the key to power is flow and efficiency. Pick up some hedman headers from O'reilly Auto Parts to replace them. Cut out the catalytic converter (if someone hasn't already). Go look for some Dart #127221 SHP Cylinder Heads. You can find them online for about $1100. These heads have 180cc runners (maintains high velocity) and a 256CFM flowrate at .500 lift. These will do great things for the stock 350 bores and fill them with fuel mixture very efficiently. These heads are also pre-equipped with springs good up to .520" of lift. Then you will want to take a look at new camshafts. I'll help narrow down to two Lunati 10120301 Street Master or Comp Cams Extreme Energy 268H. Both cams offer stable vacuum to operate all of your street vehicle equipped vacuum components as well as offer the max lift and short duration needed to get the most power from your Dart equipped 350 (likely 355 if rebuilt). However, these cams alone do not hit the max lift point. You will need to utilize a 1.6:1 ratio rocker. These can be roller tipped, full roller... whatever you like. Typical pricing about $200 for a set. Depending on the cam you choose, you will have the option to get a Cam+Lifter+rocker Kit, saving you a few bucks. Now you will have to pull all the components off to install, so you will need all new gaskets. Depending on the deal you find $120-$170 for all of the gaskets you will need. All of this with the performer 2101 (The ONLY good Qjet intake to fit under our stock hoods) you have should put you right smack dab on that 350hp 400tq mark. Also, Keep that Qjet. It is a variable flow carb up to 750CFM (800cfm on some models). It will likely need to be rejetted too.

So recap
Hedman Headers - $200
Dart Heads - $1100
Cam and Rockers - $250-$300
Gaskets $120-$170

Total Price - $1670-$1770 + weekend

FYI. You will find good deals almost always on Craigslist for unused gaskets that people don't need for dirt cheap. Saving yourself even more money.

Best of luck to you on your quest for HP's

Nick