I have a 65 Ranchero with a 289 & C4 trans. It has an Edelbrock Performer cam, and Edelbrock 4bbl & intake. I'd like to change the stock exhaust, but I'm wary of taking off the stock manifolds, for fear of breaking off the bolts in the block & it becoming a major pain. Does it make sense to use the stock manifolds, but put 2 1/2" pipes with better mufflers?
Well, 2 1/2" is too much for a mildly worked-over 289 unless you have plans to do heads in the future and a bigger cam...2" would suffice. Headers are a must otherwise you will be restricting the performance gains from what you have done so far. I wouldn't be surprised if you gained 20 HP depending on what you get. Plus they just look sweeter and more "zoomy". Funny, because I was looking yesterday at and figuring out about what header changes I will make and gulped big at how much prices have gone up!!! I like Doug's tri-Ys but nutty how much they cost now....almost doubled in price from when I first started thinking about switching my shorties to them. And also thinking about slicing my shock towers down a little (which I have done before) to make room for a 351W stroker...well, maybe just dreaming!
The bolts in small block heads rarely break, very unlike the FE engines, which break almost all the time. Go for it, they'll come out ok. And as was said, 2 1/2 is a bit big for a fairly stock engine.
Yes, it seemed strange to me but too large a diameter exhaust pipe can kill performance depending on the engine. I ran into this with my former Audi engined VW Rabbit "pocket rocket". I let the muffler shop guy talk me into a larger exhaust - a big mistake. Took the snarl out of that engine. Then had to listen to my VW racer man scold me (he liked to do that) for not asking him first. Someone else can tell me the reason. I suspect that with significant valve overlap (both intake and exhaust valves open), some exhaust back pressure is needed to keep from losing the incoming fuel/air out the exhaust.
A lot of factors are involved (camshaft/valve timing) and poor header design (or if any?) mostly...a lot of it is just "if bigger it must be better" mentality (and I have been caught up in that as well, especially carburation). Everything is a trade-off of sorts and if it was mine and I wasn't going to get headers (poor decision) I would get 2 1/2" exhaust...and decent mufflers that don't restrict...another factor in the mix.
As mentioned , the manifold bolts into the heads rarely break. 2" exhaust in front of the mufflers, tailpipes can be 2 1/4 or 2 1/2 . the stepped pipe sizes helps flow. If you are running stock heads with small valves, headers wont make a big improvement. Unless you have upgraded the cylinder heads , I wouldn't bother with headers .
I run stock manifolds on my stock-ish 289, with stock crossover, 2-1/4" exhaust and a turbo muffler. Nice torque and great mileage.
As mentioned above a lot gets into the mix...stepping is good idea but a pain with welding (you should, not just clamping)....IF you are headed towards more performance I would get headers but they are so dadgum expensive anymore. Sometimes you can find deals over the internet. $$$ is always the factor at least in my world.... I have a buddy who owns a shop and is floating a 347 stroker short block in front of me that he "stole" the other day...ugh, it's an obsession for sure!!! If I pull the plug and go for it I'll have some shorties for sale in the future....
Thanks for the tips and info, everybody. RancheroRandy, please let me know if the shorties become available. At this point, I think I'll leave it as it is. I'm not looking for better performance, I was just considering getting rid of the glass packs and putting new mufflers on.
Do some research before you buy mufflers, there a straight through and chambered mufflers each of them sound different. I run 36" thrush perforated core (not louvered core) glass packs behind the axle of my 64. They are pretty quiet at idle and part throttle, don't have exhaust drone at hwy rpms. I am running a 302 roller block, I put 351w valves in 289 small chamber heads, ported the heads, port matched the exhaust manifolds. 92 mustang cobra cam, 4 barrel and aluminum intake. Tremic T5 transmission with 3:50 gears. It's fun to drive , gets to 100 mph really quick but doesn't handle very well at that speed. It is dangerous to drive it fast. Now it needs more tire, stiffer springs , sway bars , upper control arm relocation . These early Ranchero's were not designed to go fast and handle.
Mines a cruiser. I save my speed stuff for the track, and that's with a different vehicle. I was fortunate to have lived thru the muscle car era, and my "mid-life crisis" was with Porsches. Now I'm in my "second childhood" and driving something similar to what I drove in High School. It's not about speed, it's about how it feels to drive it. And something to tinker with in my retirement. I'm almost done with what I want to do with this one, and then I'm thinking maybe a 65 Falcon wagon for the next project.
How a vehicle feels on the road really does make all the difference. I have done a lot on mine's suspension (and power) which accentuates the deficits in the steering...even with a roller idler arm, etc. I guess I'm just wanting the modern car feel or preciseness. I keep talking myself out of using my limited Ranchero bucks for rack and pinion steering instead of more power: it still has too much bump steer. Total Control Products makes an excellent swap kit which I had previously used on a '62 Ranchero and it keeps "calling my name". I like my Magnflow mufflers since that is what's this thread is about, ha! They aren't too loud (sign of age I guess?!) except with before axle dumps they reflect a lot of noise when starting-up in the garage...just ask my dog?! Here's peak, BUT, I redid how they hang (my nickname I've given myself is Re-do-it Randy, ugh!) so they tuck up closer to floor pan...
