Many options.
You can buy a progression distributor, they are electronic and just build a timing table just by typing numbers onto your phone. No springs or weights needed.
I would recommend that you decide on the clear end goal for the car so you don’t waste money doing things over if that makes sense.
don’t spend a bunch on a vacuum dependent carb if a few years from now you buy AFR heads with a healthy cam.

 

compared to a stock single cat back into dual they might come out ahead.


.A free flowing non tuned side pipes with minimal mufflering is a marginal improvement. About like stock exhaust manifolds into true dials. Neither totally help like a tuned tri y headers or 4 into 1 with x pipe and free flowing dual exhaust.

It's unintelligent to defend the poor choice of 98% of the side pipes installed 🤣

 

Engine Masters has done a few episodes on exhausts. Unfortunately, most of their videos are behind a paywall.

Here's one data extract at fixed RPMs

• Log-style, cast-iron manifolds : 474.2 hp @ 5,700 rpm / 453.2 lb-ft of torque @ 5,400 rpm
• Mid-length headers : 488.2 hp @ 5,700 rpm / 464.3 lb-ft of torque @ 5,400 rpm
• Long-tube headers : 494.5 hp @ 5,700 rpm / 474.3 lb-ft of torque @ 5,400 rpm

https://gmauthority.com/blog/2016/12...headers-video/

They used an improved 6.0L LS2 equivalent for that test. Someone can find the Dual vs. X vs H pipe video and pull the numbers. All else being equal, true-duals lose a bit to a tuned X-pipe.

So, yes, a tuned, under-car, long-tube header system into a dual 3" and X-pipe exhaust should come out ahead of an untuned, very long-tube side exit headers with a 4" open pipe. But I've never seen that experiment, and it's too costly for one of us to bother.

But we aren't comparing optimal to sidepipes. Most of us are comparing the stock L48 exhaust (2 into 1 into 2, with restrictive logs), to sidepipes. If you gain, say, *40 hp, but leave *5 or *10 more on the table, for a fraction of the cost and weight, are you going to care? Depends on what you want your car to do.

* Made up numbers warning: I have no idea what the real hp numbers are, or the ratio between a hypothetical perfect exhaust, and the very real and iconic side pipe exhaust.

 

Hey guys just another update here. So ive decided yeah i could do a Holley but they are expensive so id rather just rebuild the qjet and get new jets but im not sure on what size i Need along with the metering rods do i even have to change the rods with the jets? I’m just gonna buy a big kit from summit. What size would i need? I’m just gonna do an exhaust tune the dist for timing and tune the carb up for performance. And thats about all im gonna do performance wise for a bit. And i saw someone say i should lay out a clear goal and i think thats a good idea. This car needs some love interior and exterior it’s not too much but it’s some work. So i want to make it at least sound cool and semi fast and then fix it up. So the only performance im gonna do probably for a good amount of time is just tuning the dist and carb resetting the carb and adding side pipes. In the future i would plan to do heads and a cam but thats probably around a year in. So whats the cheapest and easiest way to obtain that im comfy resetting and rebuilding a qjet and doin side pipes the dist ive still got a lot to learn about. So what do i do? How do i go about this? And could you please add links to the parts you are referencing..

Thank you all so much

Air_drewdy

 

Don't by a kit from Summit. Buy it from Clliff (and his book!).

https://cliffshighperformance.com/

I have a 79 kit for sale in the for sale section, with an electric choke conversion, and a 79 carb core. But ask Cliff what jets to get.

 

Will do!