Cat back vs. true duals

[waldo786]

Hello all, I'm wondering if I can get some opinions here. I have an 86 MC SS that I'm having some work done too. I'm having an Edelbrock pro flo efi 3 kit put on it, new camshaft installed: XE250H (specs here: http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=83&sb=2) Edelbrock TES headers. The cam is not overly large because I want to drive this car regularly, but it is an upgrade over stock. It is actually the smallest one they sell in the extreme energy category for this engine. In dyno results in a 350 on the comp cams website it actually had higher torque and HP than the next size up. I planned on doing a 2.5" cat back system - I have a 2.5" high flow cat and the system itself with Flowmaster 50 series Delta Flow mufflers. The shop is recommending a true dual exhaust system, but I think it might be overkill for what I'm trying to do. Thoughts? Here is a link to the Dyno chart: http://www.compcams.com/Pages/401/dyno-sheets.aspx

 

[565bbchevy]

I am curious as to why you would modernize this set up with such a pricey FI system but not put a hydraulic roller cam in since I am assuming you are going more for long term reliability than you are for big power gains.
I would say with your cam choice your current exhaust set up should be more than adequate to handle the task.

 

[axisg]

x2. I would run what you already have until you don't want to run it anymore.

I am running the zr270hr retro-roller in my 5.7 and still using the TES Headers and 2.5" Cat-back exhaust. The extra cost to run duals in my case makes me want to wait a while

 

[waldo786]

Thanks for the responses. I did think about the roller cam, but the 86 block is not ready for a roller cam. Comp cams has the retro rollers you can retrofit but they are about $1k for the setup. It was about $500 cheaper for the kit for the flap tappet, but I'll be honest I keep going back and forth whether to do the roller and return the other before it gets installed.

 

[565bbchevy]

I bought a Howards roller set up for SBC last year it was about $600.
A roller cam will also make a little more power without affecting driveabilty compared to a flat tappet plus break in is a breeze and longevity is increased.
I myself plan on running a Fitech FI on the SBC I will be putting in my Regal project with the roller cam.

 

[axisg]

I have to admit the Retro-roller install in my car was a steep learning curve with me taking the timing cover off 3x and swapping out the distributor gears twice trying to keep the camshaft from walking. I only went this route as the internals of my motor were good and I don't have a garage to yank the beast out.
However if I were starting from fresh I would have sold my junk and bought a vortec era "roller" block to start fresh. Decent heads, better camshafts, better internals than any of the 70's or 80's stuff I am used to working with

 

[565bbchevy]

Really the only difference with retro roller is setting up the endplay with the cam button since there is no bolt on plate for the cam and to make it easier you can buy a Cloyes aluminum timing cover with built in cam button or a nice aluminum cover with access to the cam or buy an Ebay cover and just modify it.(What I did for my BBC)
The thing I don't like about the roller blocks is having to run a weighted flexplate even though the engine is internally balanced.