I ran across a very low mileage (20K) Vortec longblock from a 99 GMC truck for pretty cheap. I've thought about putting Vortec heads and the Vortec TPI intake on my 91 GTA 350 L98 block. My question is what issues would I have to deal with installing the Vortec longblock in my car with the TPI intake? Thx. in advance for any help.

The only issue would be the Vortec TPI base. You should be good to go.

Why not just install the longblock? You could swap over your L98 cam if you like, or get something aftermarket.

I was doing a little research and there might be a water pump reverse flow issue if I want to use a 88-92 Serpentine setup.

The serpentine water pump is reverse rotation. Neither L98 nor Vortec are reverse flow.

The 88-92(f-body)Serpentine setups have a reverse flow water pump? The L98 and Vortec are not reverse flow? I'm confused?

Will the 88-92(f-body) Serpentine setup and water pump work on the Vortec 5700 L31?

Yeah our serpentine belts and accessory brackets will bolt up no problem. The blocks should be the same as any other 1 pc RMS roller block and I've got my setup successfully bolted to two sets of Vortecs now, and I never had any problem with that either. It's pretty straightforward.

You should remove all the truck accessories anyway and bolt all your f-body stuff to it. I doubt the truck stuff will even fit in the car. I dont know about the reverse flow or not waterpump issue, but if you just throw the water pump off hte L98 on there with the rest of the serpentine system you wont have any problems. They may well be the same, though. SOme water pumps have the pulley lined up in a different spot (Farther out in front the motor or closer to the motor) and so if you're going to move the serpentine system over, jsut get a water pump to match - problem solved.

Summit calls out a reverse flow WP for a 88-92 5.0 and 5.7 in Camaros and Firebirds. 96-2000 5700 Vortec 5.7 call for a standard flow WP.

Here is the problem I see: You cannot use a standard rotation WP with a 88-92 Serpentine setup because to get all the other acc. to work they must turn the right direction and to do that you would be turning a standard WP the wrong direction.

The 88-92 Serpentine bolts right up to a Vortec engine.

What would happen if you installed a reverse flow WP on a engine that did not come from GM with a reverse flow WP?

Most GM Serpentine setups will not work in 3rd gen F-bodies because of hood clearance issues, especially truck setups.

The only reverse flow engines are the LT1 type. Reverse rotation is different and for use with serpentine setups. You should have no problem using whats on your camaro right now.

Take everything you read on summitracing.com with a grain of salt. Love 'em to death, but they get a lot of things wrong.

As stated, LT1 was the only, ever reverse "flow" engine. The water pump also happened to be driven by the cam.

Serpentine car and truck systems use a water pump that rotates in the opposite direction as the engine, and are therefore called reverse "rotation" water pumps - the flow direction is the same as always.

L98 (after '88), L31, LB9 (after '88), LO3, LO5, all those engines with serpentine systems, were standard flow (block first) and reverse rotation water pumps.

So the coolant runs thru the engine the same(besides the LT1 type)its just the acc. belt turning the WP pulley the opposite direction when they state reverse rotation-flow WP?

Ok, I just checked Autozone and Advance and they are stating the same thing as Summit did. 88-92 Camaros and Firebirds use a reverse rotation WP and 96-2000 Vortec V8 use a standard rotation WP.

Is this because of the different Acc.-Serp setups on 88-92 Camaros and Firebirds compared to a 96-2000 truck setups?

I have a 99 GMC K1500 Z71(old body style)with the L31. I'm going to check this issue I have out tomorrow.

Thx. for all the input.

That's all it is. If you use a 88-92 thirdgen water pump, you wont have any problems. It's not reverse flow so much as it is reverse rotation because of the way the belt is set up. The water flows in the same direction on all Gen I blocks. The pumps are different because of different belt systems.

five7kid, I totally agree with you about summitracing.com. I have found so many errors especially when it comes to years applicable and got errors-bad advice from the employees at the store-warehouse here in Atlanta.
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It took me awhile but I'm finally getting it. I guess I have burnt to many brain cells in my life with that wacky weed. LOL

Another question:
Can I use the L98 TPI cam in my 91 engine and install it the L31 without changing the lifter and pushrods? Are the lifters and pushrods the same in the L98 and the L31?

Yes, you can use the L98 cam in the L31 engine. See Post #2. Lifters and pushrods are the same.

Looks like I'm gong to buy the engine since it seems I won't have any issues.

Do these roller cams and lifters wear out? I have heard they last a longtime with very little wear.

the stock l31 cam is better i think

I got the specs on the stock 90-92 L98 cam but not for the L31 cam.

191/196 @50 .414/.428

GM Stock Cams
Model Number .05" Duration 1.5:1 Lift 1.6:1 Lift Lobe Sep. Notes
14093643 202/207 .404/.415 .431/.443 114.5 87 350,305man
10088155 179/194 .350/.384 .373/.410 109deg 87 305 auto
10066049 207/213 .415/.430 .443/.459 117deg 88-89 350,305
10111773 202/207 .413/.428 .441/.457 114.5 90-92 350,305

I'm weak on cam specs but it looks like the 90-92 to be a better cam. This cam chart is from TGO. http://www.thirdgen.org/mods3

well u know the stock cam works well in the l31. question is are u going to use tpi on it still?

The L31 is just a longblock No intake. I'm going to use a Edelbrock or Dickey Vortec TPI base with all the other SD TPI parts.

If I install the L98 cam I believe I won't have to do as much prom re-programming.

Vortec heads flow like crazy compared to L98 heads
SD setups are rather particular on mods

You will need a tune for the longblock swap
Why not pick a decent cam while you're at it?

I'm not looking to increase HP and Torque too much over stock. I want to stick with a roller cam and lifters. Roller cams are $300 plus
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I'm not looking to build a straight line car also.

how much are you spending on the l31

Lets just say what the heads are worth

L31 cam specs are not THAT far off the 92 TPI specs, but theheads themselves flow WAY better...plus the seqential firing order of the inectors equals better mpg. If you use the L31 ECM, distributor & wiring.

96 L31 Camshaft Profile
Intake: .275 X 1.5 = .412
Exhaust: .281 X 1.5 = .423
Lobe Separation 111 Degrees

I'm just getting and using the L31 longblock, and maybe the 90-92 L98 cam. Everything else will be from 91 TPI cars except of course the Vortec TPI intake and maybe some SLP runners.

Are the cam specs the same in L31 in trucks from 96-2000?

This engine is also coming out of a 2500 so it should be a 4-bolt main. From the research I've done.

Yes...1500=2-bolt main 2500/3500=4-bolt main

As for cam specs over the years, I don't know the specific specs through the years, but I would suspect there was some improvement through the years.

Are you going to use the Vortec distributor or the TPI one?

Also a decent roller cam is $300 plus and since the Vortec TPI intake is so hard to find used, a new one is just shy of $500 shipped.

Probably the TPI distributor. Why?

I've only been able to find specs on the 96 L31 cam
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I do know from my 99 GMC with the L31 that the distributors don't last, head and intake gaskets leak. These are common problems with the L31

The Vortec dizzy has the CPS (cam position sensor) in it for sequential firing of the Vortec injectors. IMHO a better, looking at least, cap which will not fit a standard dizzy.

As for the wiring differences, as in...can the TPI harness simply plug into a Vortec dizzy, I dunno. If so, the injector harness plug would simply be left emtpy. There would have to be a plug from the Vortec dizzy to the ECM to tell it which injector to fire when, then the ECM would have another harness piece to the injectors themselves.

Make sense? In my head I can see it all, but I'm not sure I'm explaining it right. Am I? Hope so.

Once the TPI is altogether and the plenum extension is on you can't really see the distributor.

Doesn't the Cam PS work with the Crank PS or is that just in the ECM? I had a code in my truck that was P1345 = Crankshaft position sensor / Camshaft position sensor correlation. It should say your crappy GM distributor is wasted.

I'm going to stick with the TPI distributor and make life easier.

why dont u just use a carb? dont the 2500/3500 come with 062 heads?

I'm big fan of TPI intakes and not carbs.

This one has 906 heads.

According to Mortec the 062 were on 98.

12558062...98......350..........L31 Vortec, truck, 64cc chambers, 1.94/1.5, 170cc intake port

10239906...96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves

What is the difference between the 062 and the 906? They look the same to me

Mortec info on the block:

10243880...350...95-00...2 or 4...Vortec truck, Gen.I crate motors and "ZZ4", roller cam, one piece rear seal

They have 95-00 but I believe it should be 96-00

well i am to but not when its not stock anyway. i just think its alot of trouble

You can get them way cheaper than that.. near $150 usually. $300 - $400 would get you an okay custom grind.

Please post a link to a NEW roller cam for $150. Thx.

With roller, new isn't really an issue. You can get an LT1 or ZZ4 take-out cam for $150 or less.

What kinda gains would I see from a LTI or ZZ4 cam in the L31 with a TPI intake?

I found this cam on Ebay: P/N 10185071

DESCRIPTION: CAMSHAFT Hydraulic Roller Tappet This hydraulic roller tappet is used on the 5.7-liter H.O. 350 ZZ3 & 4 engines. The duration at lash point in degrees (intake/exhaust) is 275/280; duration at .050" tappet lift (intake/exhaust) is 208/221; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 474/501. Valve lash is zero/zero and lobe centerline is 112 degrees.

u will have to get ur heads worked on to take that big of a cam.

True on the dizzy cap not being seen, but I wouldn't mind having the plug wires coming out more organized & looking better.

That, I have no idea. But, I'd suspect the ECM looks at both & adjusts timing, based on if both are reading as synced, then throws a code/adjusts the timing as needed, to try to keep them together.
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I'd think they are...But are the Vortec & TPI dizzys iterchangeable physically? I see no reason not...

And with a carb, there goes anything resembling gas mileage. Something to consider with todays gas prices.

Besides, you can make more power AND get better mileage with EFI.
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Yep. .490 is the max you wanna run on a stock Vortec head. But it's fairly easy (for a machine shop) to up the lift capability.