What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Can My 1990 Suburban 350 with a 700R4 Transmission get to 80 mph without the engine throwing a rod?

blackandgold51 said:
It does not have a tach, it has a functioning overdrive(which I use 99 percent of time except when I use "regular D" for towing), engine does have oil in it which I change every 3000 miles with either 10w40 or 20w50 regular oil(no synthetics), tire size is 35
Click to expand...

So, some assumptions on gearing based on 80 mph freeway speed.

3.08's...1655 rpm
3.42's...1838 rpm
3.73's...2005 rpm
4.10's...2204 rpm
4.56's...2451 rpm
4.88's...2623 rpm
5,13's...2757 rpm
5.38's...2892 rpm

As long as you're in overdrive, you aren't getting into anything that anyone would call high rpms.
 
tRustyK5 said:
So, some assumptions on gearing based on 80 mph freeway speed.

3.08's...1655 rpm
3.42's...1838 rpm
3.73's...2005 rpm
4.10's...2204 rpm
4.56's...2451 rpm
4.88's...2623 rpm
5,13's...2757 rpm
5.38's...2892 rpm

As long as you're in overdrive, you aren't getting into anything that anyone would call high rpms.
Click to expand...

'Cept for the 6.2 guys! :haha: :rotfl:



Your rebuilt engine should not have problems with 80MPH. If it does, you probably have something else wrong.
 
It really just seems high. I don't have a tach but 37s 4.56 and a 700. I have hit 80 before for several miles. My engine made quite the racket. It's not a pleasant sound
 
blackandgold51 said:
Suburbans from 1973 to 1991 does n have tach meters if I recall.

Unless, their were special ordered at the time
Click to expand...
Hmm...I've never seen one in a 'burb...I've had 4 of them...:dunno:
 
tRustyK5 said:
I drove my Jimmy to Blazer Bash in '03. 4.56's and 39's with an SM 465 with a NA 6.2. 2750 rpm, 1200 miles each way. It was fine, except my hearing never recovered.
Click to expand...

This is correct. Your hearing may be the most obvious issue you encounter (with a 6.2, at least). My story is much shorter (only 3 hours), but my ears were ringing for quite a while. And poor baby was *NOT* happy during those hours... :doah: :doah: :doah:

Winding up a 350 should not be an overly painful experience in comparison.
 
My k5 did 80 all the time and never threw a rod. Although it wasnt running and on a trailer, it handled it well.


This is the benefit of running the in line 7 Cummilingus 64 valve. The parts inside are so strong I usually give her a big ass shot of nitrous just to see if I can put a view port in the block but alas it's not possible.
 
tRustyK5 said:
I drove my Jimmy to Blazer Bash in '03. 4.56's and 39's with an SM 465 with a NA 6.2. 2750 rpm, 1200 miles each way. It was fine, except my hearing never recovered.
Click to expand...


My '82 K2500 with a 6.2 TH400 will "reach" 80 mph,but it feels like it is going to shake off the chassis once it tops 75 or so,the tires are old and no balance weights on any of them,it rides nice up to 60+,but I keep it off the interstates as much as possible..

I do not know what gearing it has but I'm assuming its 3:23's or 3:42's judging by the rpms at highway speeds,and how fast it'll go in each gear before upshifting..I bet it will hit 90 if I had new tires...but I wouldn't want to try it..

Once I had to borrow my brothers car,a '69 Camaro with 4:56's, a 305 V8 and a Muncie 4 spd.. and I had to go to a town 75 miles away in it...
All the way there,to me,it sounded like it was in second gear,not 4th,at 65 mph the tach read almost 3200 rpms..and like Rene,I think my hearing never fully recovered from that trip too...it had some throaty mufflers and after a few hours of that droning high revving ,I knew how NASCAR drivers must feel after a race...my hands were itchy too,like after you use a chain saw or weed eater for awhile...
I also had to fill the tank before I left,and again,to make it back !..
Got like 8-10 mph...:eek:..
 
If you have 35" tires and any gearing that was offered stock you are not revving that high at 80 mph. If you are use to driving a Civic and now go to a V-8 Suburban with dual Flowmasters I'm sure it does sound really loud when running that speed. When stock my '90 with the 6.2/TH700R4/3.73 gears/32" tires would cruise all day at 80 mph....even had a couple speeding tickets on the freeway with it.
 
6.2Blazer said:
If you have 35" tires and any gearing that was offered stock you are not revving that high at 80 mph. If you are use to driving a Civic and now go to a V-8 Suburban with dual Flowmasters I'm sure it does sound really loud when running that speed. When stock my '90 with the 6.2/TH700R4/3.73 gears/32" tires would cruise all day at 80 mph....even had a couple speeding tickets on the freeway with it.
Click to expand...
I drive with a single exhaust with 40 regular series flowmaster
 
You must log in or register to reply here.

Latest Posts

Top Bottom