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I recently bought a 79 L48 4 spd. The previous owner said it has an edlebrock performance intake, and a cam, but doesnt have the specs, as he inherited it from an estate. When I took it to a guy i know to show me how to properly set the timing and carb, first thing he said was “this thing’s got a massive cam”. It sounds mean and idles rough, but noticeably smoother after the tune up.
I want to put true dual exhaust in with an H pipe and no cats. What diameter should I look for? I’ve heard 2.5 inch to 2.75 inch. Im also looking at headers, which i’m thinking of going with shorts for more low end. The cam gives plenty once the revs get up.
Also, any guesses at what kind of power I could be at after exhaust? The goal is to get close to 300 hp, with a whole lotta torque.
Any info is appreciated.
Last edited by Cmurray79; Jan 29, 2020 at 01:51 AM.
I recently bought a 79 L48 4 spd. The previous owner said it has an edlebrock performance intake, and a cam, but doesnt have the specs, as he inherited it from an estate. When I took it to a guy i know to show me how to properly set the timing and carb, first thing he said was “this thing’s got a massive cam”. It sounds mean and idles rough, but noticeably smoother after the tune up.
I want to put true dual exhaust in with an H pipe and no cats. What diameter should I look for? I’ve heard 2.5 inch to 2.75 inch. Im also looking at headers, which i’m thinking of going with shorts for more low end. The cam gives plenty once the revs get up.
Also, any guesses at what kind of power I could be at after exhaust? The goal is to get close to 300 hp, with a whole lotta torque.
Any info is appreciated.
my 79 L48 stock 350. Has 2-1/4” exhaust no h tube no cats. Put Flowtech headers on from auto store. Coated with ceramic at home baked at home. Then wrapped with exhaust wrap. Headers fit perfectly!!!!! Changed bolts to Allen cap head bolts for ease of tieghting. Nice. Capped egr valve and waiting for nicer weather to tune it properly.
I've spent a lot of time thinking about how to do true-duals on my 80, and how to replace the undersized true duals on my 79. The main restriction is the transmission crossmember. In a 79-auto and all 80s, this is a bolt in part that can be replaced with aftermarket replacements, or modified yourself.
I got a great deal on sidepipes for my 80, so I stopped worrying about it for now, but if I change out a transmission, I'll be sure to replace the crossmember, too.
Post #35 shows one example. Below is another, likely from this Forum, but I don't know the source. I've seen lots of other examples on the Forum. I hope this helps!
I recently bought a 79 L48 4 spd. The previous owner said it has an edlebrock performance intake, and a cam, but doesnt have the specs, as he inherited it from an estate. When I took it to a guy i know to show me how to properly set the timing and carb, first thing he said was “this thing’s got a massive cam”. It sounds mean and idles rough, but noticeably smoother after the tune up.
Is the four-speed a cast-iron box or aluminum? Early 79s were shipped with the Muncie Saginaw box
Last edited by hunt4cleanair; Jan 30, 2020 at 03:55 AM.
The buildsheet will have it recorded or you must look at it...passenger side probably the best. Its either aluminum or rusted cast iron. The Dealers Invoice is not a buildsheet and therefore will not show what was installed by the factory.
Here's link to an article on the four-speeds of 78-79 along with photos of this 70s era Muncie (different than a 60s Muncie) and how to interpret the numbers, assembly and date codes.
FYI. Short tubes are for top end. Long tubes produce more low rpm torque. Short tubes are a waste of time and money unless nothing else will fit. I have some new never used Hooker Super Comps for sale but shipping cost is probably prohibitive depending on where you live. PM me if interested.
I recently bought a 79 L48 4 spd. The previous owner said it has an edlebrock performance intake, and a cam, but doesnt have the specs, as he inherited it from an estate. When I took it to a guy i know to show me how to properly set the timing and carb, first thing he said was “this thing’s got a massive cam”. It sounds mean and idles rough, but noticeably smoother after the tune up.
I want to put true dual exhaust in with an H pipe and no cats. What diameter should I look for? I’ve heard 2.5 inch to 2.75 inch. Im also looking at headers, which i’m thinking of going with shorts for more low end. The cam gives plenty once the revs get up.
Also, any guesses at what kind of power I could be at after exhaust? The goal is to get close to 300 hp, with a whole lotta torque.
Here is a picture. Hooker says they will only fit up to 1974 but that is probably because in 75 they went to Cat Convertor single exhaust crossover, but if your redoing you exhaust to duals I would think everything else would be the same. You be the judge. $200 plus shipping or local pickup. Thanks
Last edited by Vette5311; Feb 5, 2020 at 11:47 AM.
If they will fit my L98 heads, I'll take them. I am going with a custom dual exhaust system, so no cats or cross over. I'll be using an X pipe behind the trans cross member. I'll do a quick research on the fittment and get right back to you.
If they will fit my L98 heads, I'll take them. I am going with a custom dual exhaust system, so no cats or cross over. I'll be using an X pipe behind the trans cross member. I'll do a quick research on the fittment and get right back to you.
Wayne
Scroll through this for what your wanting to know about the headers then maybe call Holley.
OK, they should fit. My Zip Code is 59901, Kalispell, MT. If you want to give me the dimensions of the carton and weight, I'll compute what the shipping charge should be.
1979 L48 Performance Exhaust Help Needed
