1979 Lesabre Sport, for NHRA Stock Eliminator?

I had considered buying a set of 86/87 headers and modifying them for my car but I got such a good deal on my 83-85 ones I gave up.

For your "all out" engine the tubulars will work better. My 80 turbo, ported heads, cam, car with the wastegate at 8PSI would boostcreep up to 10 PSI on shifts with the stock manfolds. I installed cleaned up 85 tubular ones and although spool wasn't helped any (2.41's and a tight converter) the upper RPM flow is insanely better. It boost creeps up to 14-15 PSI now (WG still at 8 BTW). Boost comes in earlier, faster once it gets past 2PSI and pulls better.

Heat retention is good, but the 78-80 manifolds dont flow worth a crap. I put my finger through the ports on my 80 cast ones and between bolt holes, casting flash, and sharp corners why anybody would run them when the 83-85 ones bolt right on is beyond me. Maybe on a stock car it would be OK, but if you cam it the cast set become baggage in my opinion. The 84/85 guys are ahead of us and if cast manifolds are so good, why do they use the tubulars?

What transmission are you using? Powerglide?
You are the first person I know to compare the two back to back. I went with the cast manifold for two reasons, the won't crack like the tube headers did and every turbo theory book I read stated cast was preferred if everything else was equal. Visually, the 1979/80 and 1983/85 look similar is size to me. But if the comparison shows the tube headers are better, then the tube headers are better. Thanks for letting us know. :) (Funny, most Hot Air owners complain the tube header is too restrictive and has poor flow due to the tubes not being lined up well.)

I know why they went tube headers in 1983 - compare them to the tiny 1982 cast pieces. Those are very, very restrictive.

Too bad no one makes a better 83/85 passenger side replacement (at a reasonable price). I figure that with double the flow of the driver's side, that would be the biggest benefit.
according to the gn documentary, they went to the header style to burn contaminents off the catalytic converter better.
I should add that I went at the insides of the headers with a carbide griding bit and cut out all the overlap between the main tube and primaries. Cut out a lot on some of them which undoubtably made a difference.

I will admit that I either have a crack in mine or my crossover leaks. I am guessing its the crossover since it was REALLY pounded out at the flare between the header and crossover. if I get around to it this week I am going to smoke test the exhaust and see where its leaking. Be curious how it spools with the 3.42's and the exhaust fixed.

If I had enough time (like that ever happens) Id be lightyears ahead of where I am now. But stumbling on outdated tech, getting the car its in nice, college, life, ect is not ideal to work on projects.

Thread hijack over!
the carb is going to be your biggest hold up. its just not gonna do what you want. but thats my opinion. and no a quad wont meter E85 correctly. I personally prefer the cast manifolds.

Mass flow is low enough on this system that the tubular headers are loosing energy before it makes it to the turbine. the cast are needed to keep all the heat you can to make that long run to a crappy and inefficent turbine.

id start by maximizing everything you got first. this is how to win super stock.

all cylinders need to be within 2% of eachother in compression test, we need the motor as even as possible.
disable as much of the Emissions as possible. ditch the EGR
block off all hot water to turbo plenum.
port the shit out of the exhaust manifolds.
port the shit out of the intake
port the shit out of the turbo plenum
agree with bison go with the most advanced roller you can find.
lighten up every aspect of the car you can. get a hole saw and start swiss cheesing where no one can see.

from there it gets wild. and not safe and expensive. like ultra thin pushrods, honda rod journals, low tension rings, etc etc.
Well, no roller cam, and no touchy the intake, this is just Stock, not SS. The rest I have covered. I guess I'll just put together what I have and see what happens! If a 301 'Bird can run mid 12's under these rules, I should be able to get a 14 outta this barge...
cant touch the intake internally at all?

this is what i would concentrate on first. the intake....... if you can do anything to it, do it. cause this is your bottleneck.
Unfortunately, I cannot touch it at all. I am very limited in what I can do, which oddly enough is why I like the challenge. I'm going to start with the basics (solid HP ignition and carb rebuild), plus 3.73's and a 3000 stall converter, plus all the weight reduction and chassis tricks I can legally do, and then start slowly adding boost. I'm going to leave the stock exhaust manifolds (cleaned up) but delete the rest of the system as I won't need it, and make sure my fuel system is top notch (5gal cell, -8 lines, Holley 'blue' pump and regulator, and a cool can, plus 104 octane race gas). I can leave some weight in it, to move it down a class, then I'm shooting for a 14.05, or at my altitude at least a 14.50 et. I have all spring to dial it in, the National Open will be at my home track in August.


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i dunno about the 3.73s. your gonna unload that turbo too much. you need as much boost as low in the rpm possible... id almost jump for a 3.23 and a loose converter.
I also found that the car has 3.23's in it. I'll try them first and go from there on gears, but I have 3.42 and 3.73's at the ready...