Originally Posted by DirtyLarry (Post 7480690)

Hey Devin,

Cool! Sounds like a fun project. Yeah, the guts probably came loose on your muffler. I had a 2005 Silverado HD that did the same thing…..very annoying. Regarding the cats, if you can get away with replacing the cats with a “test” pipe like I have on my Suburban (wink, wink) you could have whoever is doing the ECM tuning just tune out the rear sensors instead of dummy sensors.

Regarding exhaust pipe size for a BBC, it seems the preferred size is 2.5” where claims of 3” or bigger takes too much back pressure way equaling loss of low end torque and anything smaller is too restrictive. I couldn’t really tell you on velocity/flow characteristics as that seems to be what appeals to each person’s ear but I can tell you that an older BBC, like the Vortec 454 you’re working on, requires a completely different muffler/exhaust configuration than an LS engine or even an 8.1L due to the different firing orders of the newer engines (1-8-7-2-6-5-4-3) compared to the older engines (1-8-4-3-6-5-7-2). The newer firing order engines absoluty need an H, X or x-muffler to sound right, otherwise they wound sounding like two poorly running 4 bangers having a shootout while the older engines like yours sound darn good with true duals, with two individual mufflers. I personally have never had an H or X pipe in an older firing order engine as I always thought they sounded good just plumbed the old school way (twice pipes with two mufflers).

My K10 has true duals, H-pipe and two individual Thrush mufflers (Cheap $30 Flowmaster knock offs). This same exhaust was on the truck when it had a 454 and sounded great but once I swapped in the 8.1L with the different firing order it sounded horrible. Added the H-pipe and now it sounds like a mix between a 60’s muscle car at WOT, cackle of a medium duty truck at low RPM and a Ferrari at cruise. Very weird, but it sounds awesome to my ear. Meanwhile, the Burb’s 8.1L is running a dual inlet/dual outlet Magnaflow X-muffler (can’t remember the exact name and I’m not home to look up the part number) but it sounds great with zero drone found with the typical dual inlet/outlet mufflers. Really quiet idle and cruise but it has a set of LUNGS at WOT almost like there is an exhaust cut out welded in somewhere. The videos posted of my Suburban are not the new Magnaflow exhaust but the old out 2” Flowmaster that sounded great with a 350 but a 50 caliber machine gun spinning at 50,000 RPM’s with an 8.1L. It was horrible. If it were me with an L29 454, I would go with cat “test” pipes and 2 individual Flowmasters or Thrush Flowmaster knock-offs (not a dual inlet/dual outlet muffler). Dual inlet/dual outlet on a 1-8-4-3-6-5-7-2 engine makes way too much interior drone for my liking. Dealt with that on my old ’98 Z71. Not sure if that helps you or adds more to the confusion but that I my offering to your question. I’m sure the heck no exhaust expert. My wife says I'm deaf anyway so my trucks may sound like crap to other people but they sound good to me now :lol:

Oh, I almost forgot....I have a Flowmaster dual in/out Big Block Muffler on a '93 C1500 with a 454 and it drones like mad. Sounds good, but the drone at throttle tip in is pretty sucktastic. It sound great on the outside though

Originally Posted by Chevy3+3 (Post 7543863)

Hey Larry I thought I read somewhere that you have had problems with your 5th gear nut on your NV4500's. I just got done with my swap over a week ago and had been driving my truck everyday and just last night developed a ringing/rattling sound only in 5th gear. The noise doesn't really change when 5th gear is under load or not.

Does this sound like a 5th gear nut problem and what have you found to be a good fix for this. I really don't have much money to throw at it and I'm told my tranny doesn't have many miles on the rebuild. I know some have welded the nut on with great results but also know that sometimes the welds break and then you must install a new shaft.

What are your thoughts, Thanks

Originally Posted by DirtyLarry (Post 7548465)

Yeah, I had 5th gear issues where getting it into 5th was like getting in an arm wrestle with the shift lever. Also had them where 5th gear screamed like crazy. NV4500’s are weird because some make more “normal” noises than others. Curious how many NV4500’s you’ve driven to compare this as a normal characteristic or something out of the ordinary. NV4500’s are finicky!

Funny you should bring this up as I just got a reman NV4500 for the Polar Bear about 3 weeks ago. The new one shifts fine but it makes a huge racket in 5th gear…not under acceleration or coast but a coast with a slight tip in of the throttle. Hard to explain the noise but it sounds like something inside is loose. The closest thing I’ve ever heard to a noise like this is when the idler gear in the NP205 in the K10 was loose and would bounce around under a slight tip on of the throttle on a partial coast when the gears are somewhat relaxed. I’ve been going round and round with the reman company where they said “No problem….ship it back and we’ll take a look”. And I’m like nooooo…..you guys send me another one so I don’t have to have my shop plugged with the Suburban for 3 weeks while this one gets shipped back, they take a look/fix then ship it back. They aren’t willing to send me another unless I pay for it then they will reimburse me once they tear into it and confirm a defect on their part. That leaves me in an awkward position with $1000 on the line hoping they will be honest and own up to an issue rather than pull some shenanigans that reman companies are famous for pulling. I guess they’ve been burned before where they won’t ship anything until they confirm the issue is theirs and not an installation error. There is no error even a moron could do with the installation that would cause this noise other than something went wrong during their rebuild. Very frustrating.

I tell ya, I am done with NV4500’s after this mess gets resolved. The next NV4500 that dies in the K10 or this burb is getting replaced with something else even if it is an automatic. Tremec makes an equivalent transmission to a NV4500 (similar dimensions, same input and output spline size and counts) that is used in Mexican and South American market GM trucks but we never got them in the US. Tempted to see what it would take to get one of those…..or just go 4L80E next go around. I’m in a real bad mood about NV4500’s lately :lol:

Originally Posted by Chevy3+3 (Post 7548476)

Sorry to hear your having sucl trouble from the transmissions. This is actually the first NV4500 I have driven. The shifts are great. I have no problem grinding during shifts or anything like that. It's a funny noise like a light pinging/rattle. It's not extremely loud. Makes me wonder if it might be normal noise. The last time I drove it I could not get it to duplicate the noise. I'm getting ready to change the oil in it (ouch $$$), lol. I've read somewhere to add an extra quart through the shift tower to properly lubricate the input bearing. After I change the oil I will just drive it and see what happens. I have to admit you have me a little worried about the NV4500. I was excited about it until your last comment, lol.

Originally Posted by DirtyLarry (Post 7548515)

It could very well be a normal noise. Run it by a trans shop and have them listen to it before you start getting worried. They do make some normal noises and some make more noises than others. Even the ZF 6 speed in my Silverado has made a noise like an alligator gurgling rocks since the truck was brand new. If you’re getting some vibrations to go along with the noise like I am getting with my new reman 4500 then that is a different story.

Originally Posted by Chevy3+3 (Post 7548538)

What type of vibrations are you getting. I do have a light occasional vibe I notice in 3rd & 4th gear at a certain RPM. Mostly a high RPM like 25-2800. Which is past my normal shift RPMs for a 454. If I push the RPMs closer to 3000 them my vibration goes aways. My flywheel is new along with my clutch and pilot bushing.

Originally Posted by Chevy3+3 (Post 7549873)

Well I drained out my trans oil which didn't look fantastic. It was darker in color. When I put the transmission in I filled the oil until it ran out the fill plug. I drained almost 4 qts from it today. I started adding oil through the fill plug on flat ground and only managed to get about 3.75 qts into it before it ran our the fill plug hole. I added an extra quart through the shift tower and got it out on the road. The shifting is smoother and it didn't quiet the trans down some. Now I can't get 5th gear to make any noise. Only sounds from the trans now I would consider normal.

Originally Posted by 68post (Post 7551611)

What are you using for fluid ? Because they are extremely picky about their fluid. Amsoil ? GM/Dodge trans fluid ?

I'm having a problem that may not relate to my NV4500, but it would have to be the transfer case if it isn't the trans ( I need to search the web again to refresh myself of the NV4500's problems and their symptoms).
http://67-72chevytrucks.com/vboard/s...d.php?t=697706

Originally Posted by DirtyLarry (Post 7548465)

Yeah, I had 5th gear issues where getting it into 5th was like getting in an arm wrestle with the shift lever. Also had them where 5th gear screamed like crazy. NV4500’s are weird because some make more “normal” noises than others. Curious how many NV4500’s you’ve driven to compare this as a normal characteristic or something out of the ordinary. NV4500’s are finicky!

Funny you should bring this up as I just got a reman NV4500 for the Polar Bear about 3 weeks ago. The new one shifts fine but it makes a huge racket in 5th gear…not under acceleration or coast but a coast with a slight tip in of the throttle. Hard to explain the noise but it sounds like something inside is loose. The closest thing I’ve ever heard to a noise like this is when the idler gear in the NP205 in the K10 was loose and would bounce around under a slight tip on of the throttle on a partial coast when the gears are somewhat relaxed. I’ve been going round and round with the reman company where they said “No problem….ship it back and we’ll take a look”. And I’m like nooooo…..you guys send me another one so I don’t have to have my shop plugged with the Suburban for 3 weeks while this one gets shipped back, they take a look/fix then ship it back. They aren’t willing to send me another unless I pay for it then they will reimburse me once they tear into it and confirm a defect on their part. That leaves me in an awkward position with $1000 on the line hoping they will be honest and own up to an issue rather than pull some shenanigans that reman companies are famous for pulling. I guess they’ve been burned before where they won’t ship anything until they confirm the issue is theirs and not an installation error. There is no error even a moron could do with the installation that would cause this noise other than something went wrong during their rebuild. Very frustrating.

I tell ya, I am done with NV4500’s after this mess gets resolved. The next NV4500 that dies in the K10 or this burb is getting replaced with something else even if it is an automatic. Tremec makes an equivalent transmission to a NV4500 (similar dimensions, same input and output spline size and counts) that is used in Mexican and South American market GM trucks but we never got them in the US. Tempted to see what it would take to get one of those…..or just go 4L80E next go around. I’m in a real bad mood about NV4500’s lately :lol:

Originally Posted by jkiersh2 (Post 7581588)

I have just started down the L18 road. What I am doing is a little different than the folks on this forum are doing but this looks like the best place to ask the questions.
My tow vehicle is a 1999 GMC PU with the 6.0L and broken exhaust manifold studs.
I just picked up a 8.1 that I just pulled out of a 3/4 ton van. What the motor has is all of the accessory hardware that is desirable if this was going into an older truck. So the question is do keep this configuration or convert to the correct setup my truck was optioned for. I am inclined to convert and possibly trade my brackets for the more common versions.

Originally Posted by silverbear (Post 7789394)

Larry, I was directed to your build while searching for answers in Crocky125 thread about parking brakes. Looking at your pics of the 9.5" semi-float rear you had in the Suburban, the parking brake cable for the passenger side enters the backing plate on the rear side of the axle tube. On the 14FF you installed, the passenger side cable enters the backing on the front side of the baking plate. My questions are: 1. Was the cable for the semi-float original to your Burb? 2.Did you use the same cable on the Full float as was on the semi-float?

I swapped in a 1999 14FF with 13"slip on drums into my 1986 K10 and I am having a little trouble with the parking brake hanging up on my passenger side. Not sure yet if it my cable routing, the way a connected it to my system of if it is the cable I purchased to use. Just looking for resources and/or options.

Originally Posted by NastyBuzzard (Post 7789445)

What do you have going on with the mirrors? They look interesting.

Originally Posted by DirtyLarry (Post 7789449)

Just cheap clip on mirror extensions. They suck and don't fit worth the hoot

Originally Posted by 83GMCK2500 (Post 7789453)

Are you familiar with the tow mirrors that exist in the style of the stainless mirrors? They have a lock ring with set screw at the mirror head that you loosen, extend mirror, and tighten up?

Originally Posted by MalibuSSwagon (Post 7789501)

I too have questions Larry. haha. A friend and I are interested in installing the stepntow bumpers on our Suburbans. You mentioned earlier in the thread you had to fab up brackets, any details on those?

Originally Posted by DirtyLarry (Post 7789456)

Hmmm, not sure. I may have saw them while searching for something when I ended up with these. Link? Pic?

Originally Posted by 83GMCK2500 (Post 7789620)

I had the passenger side mirror pane fall out of the housing of my '83 as I was driving down the highway. Caught a glint out of the corner of my eye then sparkly things in the rearview, started looking around wondering what in the world just happened.

Larry, if you get a minute I would appreciate your 8.1 input: http://67-72chevytrucks.com/vboard/s...d.php?t=721338

Originally Posted by Matt Man (Post 7828584)

Hey DirtyLarry I nominated your suburban in February totm contest.