Need your opinion....

[JHG]

My 1981 K5 has not been used for two years now, and I am starting to use it again (it feels goooood /forums/images/graemlins/smile.gif ).

I have a few questions:

1) I have to change the exhaust, it have a double 3" (to big) but have been considering 2 1/4 or 2,5". The engine is 350 carburated, with headers etc. I do like to listen to the radio without setting it to high (I think I am getting old /forums/images/graemlins/crazy.gif ). Wich one would you choose (2,25 vs 2,5)?

2) My oil pressure is around 12psi (new mechanical gauge) at idle (~600 rpm) but around 35-40psi at higway speed. The oil pressure in my 86 Transam is 25-30 at idle (305HO). I know 12psi@600rpm is enough but whas wondering if it is a sign of my engine is getting old.

3) Vaccum, I think its great, its around 18-20 at idle but around 15 at highway speed. Isn´t like it should be?

4) Trans temperature, I have a huge cooler and a B&M gauge (sender unit at the return line), the temp is little over 100 degrees F (~110). Is it to cold?

Its great driving the K5 again, at first it fealt a little strange but then I got used to it again. Now I cant wait till it starts to snow /forums/images/graemlins/pimp1.gif

Jon H.
/forums/images/graemlins/k5.gif
1981 Chevrolet Blazer K5 Silverado
350/TH350/NP208/D44/12bolt
4.88, lockers, 38" dick cepec

 

[heavy4x4]

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Wich one would you choose (2,25 vs 2,5)?

[/ QUOTE ]

Either size will work fine. I'm running a 2.5" cat-back dual. The sound quality and level will depend on what muffler you choose to run (if any).

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I know 12psi@600rpm is enough but whas wondering if it is a sign of my engine is getting old.

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Yes, 12 is a little low which probably means your engine is showing it's age, but I doubt it's anything to worry about at this point because you've got good pressure in the operating range.

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4) Trans temperature, I have a huge cooler and a B&M gauge (sender unit at the return line), the temp is little over 100 degrees F (~110). Is it to cold?

[/ QUOTE ]

Here lies the problem with putting the sender in the return line. It has already gone through the lines and coolers, and it is probably reasonable to estimate the fluid in the pan is actually closer to 150 degrees. That's not a bad number.

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Now I cant wait till it starts to snow

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Same here. /forums/images/graemlins/grin.gif /forums/images/graemlins/thumb.gif

 

[JHG]

I cant decide wich size is better. Probably I will let the shop decide for me.

I have been considering getting another sender unit for the temp gauge (to put in the pan) so I can see both the temp of the fluid comming from the cooler and the temp in the pan. The only problem is that over here I cant get a sender unit without having to buy another gauge.

I didn´t have to wait long, it just started to snow /forums/images/graemlins/smile.gif

Jon H.