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350 is tired, what are my options?

TheBeast_88K5

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My '88 K5 has the stock 350 in it.
It was rebuilt around 25K ago, but has almost 200K on the block.

I'm in California.
So, I think my only option is a crate 350.

I was thinking a GM 350/290.
But, I don't know much about engines.
Nor smog legality, for swapping engines.

The way the law reads,
is that I need to have the same year or newer motor;
With all applicable smog equipment/ evap canister...

So is the 350/290 a "straight swap"? :dunno:

I searched this subject, but all the info is either out-dated, or not credible.


Someone school me on crate engine swaps, in California.
Thanks in advance.
 
I am wondering why you would need to swap if you just rebuilt it 25k ago?

I am not a mechanic, just a pathetic home wrench. I'm curious what issues have risen to say the engine is tired?
 
I was wondering the same thing.:confused:..That would be like somebody restoring a truck putting 20k on it and taking it to the dump because the total mileage hit 200k.That engine should go a lot longer before it needs another rebuild.Unless your leaving something out like you beat the living piss out of it and never changed the oil.
 
I would try to find out if theres a smog legal way you can run a vortec 383. Thats the ticket for a small block truck IMO
 
I am wondering why you would need to swap if you just rebuilt it 25k ago?

I didn't rebuild it.
The PO did... and he wasn't too bright. :doah:

I just want a peppier, if thats even a word, engine.
This one doesn't have anywhere near the power it should.

It's good runner, but I wouldn't trust it to get me a few hours away.
:dunno:



I would try to find out if theres a smog legal way you can run a vortec 383. Thats the ticket for a small block truck IMO
I would LOVE to to throw a Vortec 383 in here.
I'm gonna check on that... :thumb:
 
that alone would make it feel a bit sluggish.

in an ideal world you would have 4.56's for 35's or 4.88's for 37's as a reasonable setup for a daily driver type rig. those 10 bolts may be under some duress with 37's imo.


have you done a compression test yet? i'd think on doing some work to the intake and exhaust.


edit: i just saw your sig thing and the axles you have.
 
I would try to find out if theres a smog legal way you can run a vortec 383. Thats the ticket for a small block truck IMO
the mid 90's 4 bolt main blocks are a good starting point IMO, the Vortec heads are nice but they don't a heat crossover/ EGR. So if you run a Vortec head, you will need to run a newer style EGR (I think electric?) to get it to pass smog. You mine as well run an entire motor swap if you want Vortecs.

Or modify an older intake, with proper EGR, and at least get the look down.


Newer 90s 4 bolt main, with aftermarket EGR heads. Good internals and properly set up TBI. :waytogo: You can do a 383, but you'll need to dive head first into fuel injection being an '88.
 
It would be a good idea to see if you need a new engine before spending money on a rebuild or new crate. Just because it doesn't feel peppy could be a number of things.
 
It would be a good idea to see if you need a new engine before spending money on a rebuild or new crate. Just because it doesn't feel peppy could be a number of things.

I'll look into it.

It has a bit of "lag", being on 36's and 4.10's.
I'll admit that.

But, it runs like a 305, more than a 350... :dunno:
(and I know fer damn sure, it's a 350.)

I guess a compression test, etc., is in order.

Something tells me, that I'm about to learn waaay more about engines, than I ever wanted to know.... :D
 
I'll look into it.

It has a bit of "lag", being on 36's and 4.10's.
I'll admit that.

But, it runs like a 305, more than a 350... :dunno:
(and I know fer damn sure, it's a 350.)

I guess a compression test, etc., is in order.

Something tells me, that I'm about to learn waaay more about engines, than I ever wanted to know.... :D

Check the compression, tune it up, get it running right, but I still think the gears and tire size are the issue. If you can get your hands on some 31s or 33s for a few hours, swap 'em and see what you think.
 
Check the compression, tune it up, get it running right, but I still think the gears and tire size are the issue. If you can get your hands on some 31s or 33s for a few hours, swap 'em and see what you think.

Compression test will be done this afternoon.

I know the truck would be a lot quicker on 33's.
I also have the added weight of the 14b, and bigger tires.

Meh.
Compression test, and tune up first.

I guess I'll go from there.
Thanks for the help guys. :thumb:
 
You would be surprised what a tune up can do...

My 87 had over 300k on the clock when I bought it. All I did was change the plugs, wires, cap, and air filter. You wouldn't believe the difference it made, it runs like a champ, so far zero issues with the engine.

My gearing is numerically low 3.73 (stock gears & axles), but I'm only running 33s. I would rather save the cash and upgrade axles then swap gears, so it can be sluggish at take off.
 
My 87 had over 300k on the clock when I bought it. All I did was change the plugs, wires, cap, and air filter. You wouldn't believe the difference it made, it runs like a champ, so far zero issues with the engine.


Yea...

I've swapped the Air cleaner (K&N), Plugs, Wires, Cap, Rotor, Dizzy, Coil, added an MSD box, and Rev limiter, and rewired most of the truck's electrical.

(All ignition components are MSD.)

and, fwiw, The Ignition system made a HUGE difference


The Tranny, and T-case are newly rebuilt, as well.
Not to mention the Custom-tuned TBI chip (I run 91 Octane)....

That's why I'm so frustrated.
This truck should pull HARD.

Even w/ 4.10's on 36's... :dunno:

Am I just expecting too much?

Edit:
I also have a slightly higher duration cam.
At least that's what the PO said....
The truck has slight camming tone to the exhaust.

But I dunno.
That could be a fuel system issue, for all I know. :doah:
 
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Even w/ 4.10's on 36's... :dunno:

Am I just expecting too much?

yes, you are, I'm running 35's & 4.10's and it's definately NOT a sports car...it works, drives me around just fine, but definately lags pep from stoplights and such.

It's a truck, ya want fast, go bigger motor or take metal and stuff off the truck, lighten it up.

Definately new gears will help that get up & go feeling though.
 
Yea...

I've swapped the Air cleaner (K&N), Plugs, Wires, Cap, Rotor, Dizzy, Coil, added an MSD box, and Rev limiter, and rewired most of the truck's electrical.

(All ignition components are MSD.)

and, fwiw, The Ignition system made a HUGE difference


The Tranny, and T-case are newly rebuilt, as well.
Not to mention the Custom-tuned TBI chip (I run 91 Octane)....

That's why I'm so frustrated.
This truck should pull HARD.

Even w/ 4.10's on 36's... :dunno:

Am I just expecting too much?

Yeah, I would be frustrated too, but it sounds like a good investment.

If your gonna run 36s anyway might as well change the gears?

See if there is a difference, before you drop more money into another motor, and still need to change gears to help improve performance.:dunno:
 
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