Glasspacks - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68gmcjon · 02-04-2003, 08:49 PM

If i have mufflers that just clamp on to my pipe couldn't i unclamp them and put in glass packs that are relatively the same size? or will i have to cut?

HotRod929 · 02-04-2003, 08:52 PM

You sould just be able to clamp the glass packs in so long as they are the same length and diameter as your old one. However glasspacks tend to be longer that your usual muffler.

HotRod

68gmcjon · 02-04-2003, 09:15 PM

I know they do tend to be longer. Which are better the longer or shorter glasspacks, or is there a change in sound?

MU72 · 02-04-2003, 09:30 PM

Longer glasspacks are quieter and more mellow. The shorter ones are louder and more aggressive. If you don't want it to be too loud you should go with 18 or 24 inchers. Or you could do like I did and go all out with 12 inchers. Sounds great

68gmcjon · 02-04-2003, 09:56 PM

Barn or anyone in the SC kansas area know where i can get some cheeeep glass packs?

71Seth · 02-04-2003, 10:04 PM

I have 12" pacs on my 71. Truck sounds very very good. Really gets attention comming out of a curve and down a stright away, or just good ole roasting of the tires. But then again i would run open headers if I could!!!!!! :-)

casey · 02-04-2003, 10:47 PM

Changing your mufflers really depends on weather they welded those b@tchs on or not , thats a little trick those muffler shops like to play, welding mufflers on, they never did that from the factory, and you used to be able to change mufflers no problem.And as far as glasspacs go you can use any straight through muffler and get great sound, theres some real cheapes out there that will work great for playin the pipes, don't pay for the name.

benwantland · 02-07-2003, 02:52 AM

http://www.racerpartswholesale.com/tbolt1.htm I got 2 12" glasspacks from these guys for $25 shipped for my Ford. Of course, they use a louvered core, which makes them a little quieter and also slightly more restrictive, but I just needed cheap mufflers. You can get Dynomax glasspacks at Advance Auto or from www.summitracing.com for under $20 each. They are my favorite becuause they have smooth cores and also are availible in a lot of different configurations.

Oborny71 · 02-07-2003, 05:05 PM

like mentioned earlier, some muffler shops weld you mufflers on. Any good muffler shop will only clamp them on so that they can be easily changed, and you don't weld every thing because your exhaust system needs to be able to take a little bit of "twist" in it. If you weld everything your chances of blowing exhaust gaskets is greater. Just some of my previous experiances

HotRod929 · 02-07-2003, 05:29 PM

What would the sound difference be b/w a 26" glasspack and an 18" glass pack? Would it be very noticable? Thanks

HotRod

crazy longhorn · 02-07-2003, 06:10 PM

I think there are a lot of "myths" about welded exhaust! I worked in a muff shop for about a yr, & we didnt weld eveything.....or weld things to get a repeat customer over parts he couldnt change. A lot of guys would request a welded system (yes sir!), & some would say "I dont want anything welded" (again, yes sir!). Personally, I prefer a welded system & my longhorn is welded. As far as taking a welded system apart......no problem, I have a torch! the system on my longhorn was done on the floor in my garage, & has a welded H pipe,muffs, & tailpipes. ...it hasnt caused any problems. I have a straight run from the headers to the muffs(a 3 degree kink in the pass side to make line with the collector), & 2 notched crossmembers(1 custom from scratch). thje 3" tail pipes are mandrel bent, & exit ahead of the rear wheels.....yes it loud! As far as glass pcks, I dont like them.... but if you run them the longer ones are a lot more mellow......& stick them as far to the rear as you can , or the heat will burn the packing out......then you might as well have saved the cash & just ran pipe. Good luck.....crazyL

02-04-2003, 08:49 PM	#1
68gmcjon Got earplugs? Join Date: Mar 2002 Location: Winfield, Kansas Posts: 556	Glasspacks If i have mufflers that just clamp on to my pipe couldn't i unclamp them and put in glass packs that are relatively the same size? or will i have to cut? __________________ 1968 GMC Original A/C, bucket seats, PS,PB 396 bored to 402, Dynomax cerama-coat headers, Super 40 Flowmasters, 272/284 Crane cam, Crane gold roller rockers, holley 750 cfm double pumper, Edelbrock Performer RPM intake, HEI ignition, 9.5:compression Alltogether 411HP and 446ft/lbs Dana 60 w/ 3.54 gears Turbo 400 tranny Why would you have anything other than a big block? HAHA

02-04-2003, 08:52 PM	#2
HotRod929 Registered User Join Date: Mar 2002 Location: Bondurant, IA but in Worcester, MA for school Posts: 767	You sould just be able to clamp the glass packs in so long as they are the same length and diameter as your old one. However glasspacks tend to be longer that your usual muffler. HotRod __________________ 1970 Chevy C-20 350 V-8 Turbo 350 w/ shift kit Dana 60 w/ 4.10 gears AND Powr-Loc POSI New Additions: Summit Headers 135amp alternator Proform HEI Edelbrock 1406 600cfm carb Sunpro Tach Powr-Loc POSI Edelbrock Performer RPM Intake MSD 6A Ignition Box AIM: HotRod929 Visit My Site: http://1970chevy.netfirms.com/

02-04-2003, 09:15 PM	#3
68gmcjon Got earplugs? Join Date: Mar 2002 Location: Winfield, Kansas Posts: 556	I know they do tend to be longer. Which are better the longer or shorter glasspacks, or is there a change in sound? __________________ 1968 GMC Original A/C, bucket seats, PS,PB 396 bored to 402, Dynomax cerama-coat headers, Super 40 Flowmasters, 272/284 Crane cam, Crane gold roller rockers, holley 750 cfm double pumper, Edelbrock Performer RPM intake, HEI ignition, 9.5:compression Alltogether 411HP and 446ft/lbs Dana 60 w/ 3.54 gears Turbo 400 tranny Why would you have anything other than a big block? HAHA

02-04-2003, 09:30 PM	#4
MU72 Registered User Join Date: Sep 2002 Location: Maryville Mo Posts: 122	Longer glasspacks are quieter and more mellow. The shorter ones are louder and more aggressive. If you don't want it to be too loud you should go with 18 or 24 inchers. Or you could do like I did and go all out with 12 inchers. Sounds great Attached Images __________________ 72 Cheyenne 1/2T LWB original ochre/white 09 Silverado ECSB 76 International ScoutII

02-04-2003, 09:56 PM	#5
68gmcjon Got earplugs? Join Date: Mar 2002 Location: Winfield, Kansas Posts: 556	Barn or anyone in the SC kansas area know where i can get some cheeeep glass packs? __________________ 1968 GMC Original A/C, bucket seats, PS,PB 396 bored to 402, Dynomax cerama-coat headers, Super 40 Flowmasters, 272/284 Crane cam, Crane gold roller rockers, holley 750 cfm double pumper, Edelbrock Performer RPM intake, HEI ignition, 9.5:compression Alltogether 411HP and 446ft/lbs Dana 60 w/ 3.54 gears Turbo 400 tranny Why would you have anything other than a big block? HAHA

02-04-2003, 10:04 PM	#6
71Seth Registered User Join Date: Dec 2002 Location: calvert city, ky Posts: 282	I have 12" pacs on my 71. Truck sounds very very good. Really gets attention comming out of a curve and down a stright away, or just good ole roasting of the tires. But then again i would run open headers if I could!!!!!! :-) __________________ 97 ext cab 4x4 04 pontiac grand am 05 honda rancher AT (yellow) 71' C-10 swb sb400 th350 .040, 292 Mag comp cam, high rise Edelbrock w/750 duel feed Holley, Accel super coil and wires, B&M ratchet shifter

02-04-2003, 10:47 PM	#7
casey Registered User Join Date: Jan 2003 Location: Kelowna B.C. Canada Posts: 2,048	Changing your mufflers really depends on weather they welded those b@tchs on or not , thats a little trick those muffler shops like to play, welding mufflers on, they never did that from the factory, and you used to be able to change mufflers no problem.And as far as glasspacs go you can use any straight through muffler and get great sound, theres some real cheapes out there that will work great for playin the pipes, don't pay for the name.

02-07-2003, 02:52 AM	#8
benwantland Registered User Join Date: Oct 2002 Location: Iowa Posts: 71	http://www.racerpartswholesale.com/tbolt1.htm I got 2 12" glasspacks from these guys for $25 shipped for my Ford. Of course, they use a louvered core, which makes them a little quieter and also slightly more restrictive, but I just needed cheap mufflers. You can get Dynomax glasspacks at Advance Auto or from www.summitracing.com for under $20 each. They are my favorite becuause they have smooth cores and also are availible in a lot of different configurations.

02-07-2003, 05:05 PM	#9
Oborny71 Registered User Join Date: Apr 2001 Location: Lincoln, Nebraska Posts: 587	like mentioned earlier, some muffler shops weld you mufflers on. Any good muffler shop will only clamp them on so that they can be easily changed, and you don't weld every thing because your exhaust system needs to be able to take a little bit of "twist" in it. If you weld everything your chances of blowing exhaust gaskets is greater. Just some of my previous experiances __________________ 67 Chevy SWB - goal of a 1,000 hp weekend cruiser

02-07-2003, 05:29 PM	#10
HotRod929 Registered User Join Date: Mar 2002 Location: Bondurant, IA but in Worcester, MA for school Posts: 767	What would the sound difference be b/w a 26" glasspack and an 18" glass pack? Would it be very noticable? Thanks HotRod __________________ 1970 Chevy C-20 350 V-8 Turbo 350 w/ shift kit Dana 60 w/ 4.10 gears AND Powr-Loc POSI New Additions: Summit Headers 135amp alternator Proform HEI Edelbrock 1406 600cfm carb Sunpro Tach Powr-Loc POSI Edelbrock Performer RPM Intake MSD 6A Ignition Box AIM: HotRod929 Visit My Site: http://1970chevy.netfirms.com/

02-07-2003, 06:10 PM	#11
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	I think there are a lot of "myths" about welded exhaust! I worked in a muff shop for about a yr, & we didnt weld eveything.....or weld things to get a repeat customer over parts he couldnt change. A lot of guys would request a welded system (yes sir!), & some would say "I dont want anything welded" (again, yes sir!). Personally, I prefer a welded system & my longhorn is welded. As far as taking a welded system apart......no problem, I have a torch! the system on my longhorn was done on the floor in my garage, & has a welded H pipe,muffs, & tailpipes. ...it hasnt caused any problems. I have a straight run from the headers to the muffs(a 3 degree kink in the pass side to make line with the collector), & 2 notched crossmembers(1 custom from scratch). thje 3" tail pipes are mandrel bent, & exit ahead of the rear wheels.....yes it loud! As far as glass pcks, I dont like them.... but if you run them the longer ones are a lot more mellow......& stick them as far to the rear as you can , or the heat will burn the packing out......then you might as well have saved the cash & just ran pipe. Good luck.....crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....



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