The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 04-23-2003, 12:00 AM   #1
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,087
Muffler gets tossed

Today I decided I no longer liked my crappy muffler that had a hole in it, so my friend and I cut it off. My 'lil 305 bark is now much worse than its bite! At idle & high RPM it sounds sweet, but inbetween, it sounds like a friggen tractor I'm getting a new muffler and keeping my old tips. they are just taking a break & are getting polished. Anyone else running without a muffler? Mine isn't loud enough to break any laws - must be the cat. plugging it up. I did gain some horsepower though!!!
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 04-23-2003, 02:12 AM   #2
TIMSPEED
 
TIMSPEED's Avatar
 
Join Date: Jan 2003
Location: Modesto, CA
Posts: 1,321
Wanna buy a 3" in/out flowmaster? I have it on my truck now, and it's LOUD!
__________________
I have a few cars...
See Them Here
TIMSPEED is offline   Reply With Quote
Old 04-23-2003, 02:18 AM   #3
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,087
Nah, but thanks. I want to get an Aeroflow. Does anyone have a spare set of 350 heads I could have or buy? It would make this 305 have a little more power.

Oh yeah - my uncle told me to open the plug on the cat. and drain out all the pebbles. Anyone done this? Will this pass smog as long as my motor is in good shape?
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 04-23-2003, 02:31 AM   #4
Mike76251
Senior Member
 
Join Date: Mar 2003
Posts: 2,499
Wouldn't 350 heads lower your compression too much?
I think the 305 heads have a 58cc chamber and most 350 heads have a 76cc chamber.
Mike76251 is offline   Reply With Quote
Old 04-23-2003, 02:51 AM   #5
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,087
Not sure, but 305 valves are small and 350 heads would allow it to breath easier making more horsepower. Not to mention a better sounding rumble!
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 04-23-2003, 02:59 AM   #6
Mike76251
Senior Member
 
Join Date: Mar 2003
Posts: 2,499
Another thing I remembered...
I have heard from some people that 350 heads have a wider chamber and if you put them on a 3.74" block the valves may hit the top edge of the bore.
Mike76251 is offline   Reply With Quote
Old 04-23-2003, 11:32 AM   #7
1FaastC10
Account Suspended
 
1FaastC10's Avatar
 
Join Date: Oct 2002
Location: Elkhart, IN
Posts: 6,399
Tyler, just drop a 350 in it already!
1FaastC10 is offline   Reply With Quote
Old 04-23-2003, 03:26 PM   #8
78' Silverado
\/ My Loves \/
 
78' Silverado's Avatar
 
Join Date: Mar 2003
Location: Midland,Texas
Posts: 462
Lucky for me I got no cats haha. Anyways....Why don't u like Flowmasters.
__________________
78' Silverado - Blue - (In a Coma)
04' Silverado -Red-

383 Stroker in progress for the 78'!!!
78' Silverado is offline   Reply With Quote
Old 04-23-2003, 07:46 PM   #9
79BIG10
I'm back with 2nd truck!
 
79BIG10's Avatar
 
Join Date: Feb 2002
Location: Texas
Posts: 3,774
Quote:
Originally posted by 78' Silverado
Lucky for me I got no cats haha. Anyways....Why don't u like Flowmasters.
I've got Flowmasters now and so want to get rid of them for the Aerochambers. I've heard them in person and there's so much more difference in quality of sound, cheaper and flow so much better. If I had someone buy my Flowmasters off me I'd buy a set of Aerochamers ASAP. Flowmasters sounded good when they first came out but now they are not the best thing out there. Do a check on Ebay and see how many Flowmasters used are being sold there compared to Aerochambers.
__________________
1979 Chevrolet Bonanza Big10 "Tootsie Roll"
1985 Chevrolet Silverado (wife's)
Member of the Southern Bowties Club

"Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson
79BIG10 is offline   Reply With Quote
Old 04-23-2003, 08:53 PM   #10
low 84
Registered User
 
low 84's Avatar
 
Join Date: Jan 2002
Location: Houston, TX
Posts: 2,144
Quote:
Originally posted by Mike76251
Wouldn't 350 heads lower your compression too much?
I think the 305 heads have a 58cc chamber and most 350 heads have a 76cc chamber.
i definatly agree on this one. if you swaped them out for smog 350 heads your compression is gonna be so incredibly low, i don't care how big the valves are thats gonna run ten times worse than with your stock 305 heads.
__________________
'51 F100, backhalf with a narrowed 9 and coil overs, 18.5" mickeys, monte front clip, +400" sbc in the works

'05 1500 Crew Cab

RIP
'84 swb 5/7 drop, solid cammed 408 w/ fully ported dart heads, th350 w/ 10 inch hughes, 12 bolt w/ 3.73 richmonds and a locker
'80 swb 4x4 in progress: 7" lift, 350 th350/np205, d44 and 1.5" ORD tie rod, 14BFF w/discs , armored diff covers, 40" MTR's
low 84 is offline   Reply With Quote
Old 04-23-2003, 09:41 PM   #11
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,087
Damn. I thought I heard of someone doing it, but I guess not. Grrrr!

Quote:
Originally posted by low 84


i definatly agree on this one. if you swaped them out for smog 350 heads your compression is gonna be so incredibly low, i don't care how big the valves are thats gonna run ten times worse than with your stock 305 heads.
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 04-23-2003, 09:47 PM   #12
86SILVERADO
Registered User
 
86SILVERADO's Avatar
 
Join Date: Dec 2002
Location: Hills of Western Mass
Posts: 626
It is common for street rodder types (just not in that bracket myself) to put 305 heads on a 350 to up the compression but not the other way around.
86SILVERADO is offline   Reply With Quote
Old 04-23-2003, 09:50 PM   #13
popdad
Registered User
 
Join Date: Mar 2003
Location: manderson wyoming
Posts: 20
i drained the bbs out of a cat before and a motor soft plug will go back in the hole not sure about the smog diff thou i did it to a olds in ohio and never got in trouble it did make a diff and more power on its motor which was a 307 good luck popdad
popdad is offline   Reply With Quote
Old 04-23-2003, 10:09 PM   #14
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,087
thanks popdad. I wanted SOMEONE to answer my question. I guess I'll do that and keep the pebbles just in case.
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 04-23-2003, 10:50 PM   #15
Mike76251
Senior Member
 
Join Date: Mar 2003
Posts: 2,499
I did not answer that part because you live in the People's Republic of Kalifornia.
Draining the catalyst will cause you to fail that state's inspection.
The sniffer that goes up your truck's pipe will show that quick like.
Quote:
Originally posted by apstguy
thanks popdad. I wanted SOMEONE to answer my question. I guess I'll do that and keep the pebbles just in case.
Mike76251 is offline   Reply With Quote
Old 04-23-2003, 11:00 PM   #16
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,087
Depends if I get the right person to test it.
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 04-23-2003, 11:16 PM   #17
84Stepper
Registered User
 
84Stepper's Avatar
 
Join Date: Feb 2003
Location: Edmond, Oklahoma
Posts: 425
Man Cali must suck for custom cars!
__________________
84 Chevy Stepside, 350, TH350, 268h
Comp cam, Hooker headers, MSD
Pro Billet, Edelbrock Performer manifold
and 1604 carb, 40 Series Flowmasters
dumped, and Western Chassis 3/5 drop w/ c notch. New 3:73 Eaton Posi
84Stepper is offline   Reply With Quote
Old 04-23-2003, 11:36 PM   #18
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,087
DON'T get me started . . . . . . . . ::grumble::
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 04-24-2003, 04:09 AM   #19
low 84
Registered User
 
low 84's Avatar
 
Join Date: Jan 2002
Location: Houston, TX
Posts: 2,144
Quote:
Originally posted by apstguy
Depends if I get the right person to test it.
if you can get someone to hook you up on the inspection then your better off just removing the whole cat.
__________________
'51 F100, backhalf with a narrowed 9 and coil overs, 18.5" mickeys, monte front clip, +400" sbc in the works

'05 1500 Crew Cab

RIP
'84 swb 5/7 drop, solid cammed 408 w/ fully ported dart heads, th350 w/ 10 inch hughes, 12 bolt w/ 3.73 richmonds and a locker
'80 swb 4x4 in progress: 7" lift, 350 th350/np205, d44 and 1.5" ORD tie rod, 14BFF w/discs , armored diff covers, 40" MTR's
low 84 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 01:33 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com