I have a LG4 with a 4bbl Quadrojet carb. in good condition. I want to add some horses by changing from the OEM manifold to some headers.
I need to know which ones to purchase and what they cost?

I also plan on adding a hiflo cat. Should I hollow it out and how do i do that? I want that throaty sound.

What do you suggest?

 

I like my setup (in da sig)

 

Don't buy a hi-flo cat just to gut it. Thats a big waste of money. When you gut the cat you are ripping out everything inside pretty much making a hollow pipe. So there would go all the hi-flo honeycomb you payed for. If you plan on gutting do it to the stock cat.

 

Rule #1: Do NOT get any part of your performance exhaust that is made to fit an LG4.

Rule #2: Get the pieces for your performance exhaust that are made for '86-'91 TPI single cat.

Yes, you've got an LG4, but you don't have to get LG4-like parts in order for them to fit. If you follow Rule #2, you'll have a good-flowing system that will all fit together on your car.

Cost? $300-$600 for emissions-legal headers & y-pipe. $120 for direct-fit 3" high-flow cat (if you get a lower-priced universal cat, you'll spend the difference & more getting it into the system). ~$250-$400 for high-flow 3" cat-back (depending upon your taste in sound; single, dual-opposite, or dual-same-side tail pipes, etc.).

Rule #3: Get rid of that LG4 air cleaner. It's a restrictive piece of junk, fit for a four-banger.

Rule #4: Enjoy the performance increase until the itch for more strikes. Then you'll be doing cam, heads, intake, ignition, torque converter, shift kit, gears, subframe connectors, poly bushings, ...

In case you were wondering, Rule #4 is never, ever broken...

 

all cats are "high-flow" now a days. Pellet cats are long gone.

 

Okay "five7kid", I have the front and back of my system already with the K&N open air filter and flow 80 muffler plus tips. Now I need to know which brand Cat and headers. I will order them for a TPI sine they will fit the LG4. I need to know brand. BTW I currentley have 2 1/2 pipes to the Flow. Can this change with the y pipe, heasders and cat.

 

Summit carries a direct-fit Catco brand for the price I quoted (actually $116.95, I think).

There have been posts about a 3" I-pipe only, but I haven't paid too much attention to them (like this one https://www.thirdgen.org/techbb2/sho...hreadid=110402). Or, that may be something you can have fabricated by an exhaust shop without spending an obscene amount.

Is your Flow 3" inlet? 2-1/2" will probably suffice for an otherwise stock LG4.

 

Here might be a ideal for your cat (give it a bone)...
Look @ bottom of page....if you get one in the near future please post a review...I'm thinking of getting one for/while doing the engine swap deal, Hope this helps
http://www.macperformance.com/macsto...o/cmrohdr.html