91 350 Rebuild

Does anyone know of a trailer-towing (torque) cam that is ok to use in this engine and still be compatible with the original ECM? It is a two bolt-main block and is being bored .040 over, and is out of my

91 GMC C1500. I tow a 30' Jayco 4 or 5 times a year. Thanks in advance. Kevin
Reply to
KV
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I would suggest starting with

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at the below article. I am NOT endorsing Crane Cams, but they have had the most available info that I could find on cam grinds for all applications.

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Eightupman

Reply to
Eightupman

"KV" wrote: > Does anyone know of a trailer-towing (torque) cam that is ok > to use in this > engine and still be compatible with the original ECM? > It is a two bolt-main block and is being bored .040 over, and > is out of my > 91 GMC C1500. I tow a 30' Jayco 4 or 5 times a year. > Thanks in advance. > Kevin

Personally I would focus less on a cam and more on gear ratio as that is what makes or breaks a tow vehical. If you are running stock tires, you want 4.10 gears for that sized trailer and if you are running over stock tires size, try a 4.56 and you will not be disapionted in the towing improvements. ONe more comment if I may, the factory 10 bolt is not the strong of a rear axle and would no be my first choice for towing that much weight a lot wear wise. If you plan to keep the vehical for a while you should consider finding a 9.5 inch 14 bolt semi floting rear axle that they used in LD 3/4 ton trucks of that body style. Same hub lug pattern and a much stronger axle that will handle that towing with little effort. I have a 2005 Z71 loner will my truck is in for ABS warranty work. It has a 310hp 5.3 with 3.42 gears and the sticker even say HD towing package too. It is a DOG in OD and not to much better in 3rd at speed. I can only imagine how bad it would suck towing with those gears too.

Reply to
SnoMan

Thanks guys I will check out the Crane website. I thought, since the engine was apart anyway, I would try to find out if there was a cam out there that might help a little. As for the rear-end ratio, prior to the engine and tranny trouble I have had recently, I had noticed a driveline howl that I suspected may be coming from the rear end. When I look into that I will definitely consider switching ratios. Any idea if the speedo can be corrected after this is done? Thanks again Kevin

Reply to
KV

Not sure if the 91 is the same as a 92, but the shop that did the tranny on my 92 burb said they couldn't be calibrated easily, if at all. Somthing about them being electric. I could be off in this, but figured it might give you a starting point.

Good luck...

Reply to
MASTER Brian

Brian If your 92 Burb has the 700R4 (non-electronic), you and I have the same tranny. If that's the case then reprogramming mine ( or whatever is req'd) isn't likely to be easy. Thanks for the info Kevin

Reply to
KV

Why reprogram it? I have a 89 burb with a 700R4 and 172K on it to and it still works great and I would not change a thing about mine and I which my 2000 4L80E in a my K3500 shifted as predictably and reliably as my old 700R4.

Reply to
SnoMan

Sno What I meant was somehow reprogramming the ecm to correct for the speedo error after changing the rear-end ratio. Have a look back at some of the previous posts in this thread for clarification. I agree with you...the 700R4 was very predictable etc. right up until the day it spun. Now for some upgrades - Corvette spool, shift kit and a couple other goodies. Kevin

Reply to
KV

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