vin x, vin w

[whitetrash982]

i know on 98+ s-10's with the 4.3 , has either a X or a W is the 8th on the vin , the x being the 190 HP one , and the W being 160. now then , i have a 99 s-10 4x4 ex cab 5 spd , with you guessed it , a vin W. i hear tell the only diff is the heads on the vin X...is this true or not? and if not , what else is diff , PCM , wireing...bolt pattern , anything , cuz i wanted to slap the vin X heads on my truck, any info is greatly appreaciated

[rlith]

Originally Posted by whitetrash982

i know on 98+ s-10's with the 4.3 , has either a X or a W is the 8th on the vin , the x being the 190 HP one , and the W being 160. now then , i have a 99 s-10 4x4 ex cab 5 spd , with you guessed it , a vin W. i hear tell the only diff is the heads on the vin X...is this true or not? and if not , what else is diff , PCM , wireing...bolt pattern , anything , cuz i wanted to slap the vin X heads on my truck, any info is greatly appreaciated

Actually you have it a little backwards...In all years the VIN W was the more powerful motor... That said...

With the 96+ the differences between the VIN W and X were minor... The Vin X runs 180, the VIN W runs 190. The difference is ecm programming and a slightly smaller cam in the VIN X... That's it..No difference in the heads.

For the 92-95 Differences are a little more noticeable. Vin W was 195
HP and use CPI (Central port Injecion). Vin X was 160 hp and use TBI (Throttle body injection) The vin w also had a larger cam. Other than that the blocks themselves are identicle through all years.

As I said about the heads, 96-current all heads are the same regardless of VIN W or X. The 95and below Vortec heads don't flow quite as well as the 96+ heads, but by 95 the vortec heads were being thrown on both VIN W and VIN X motors.

If you're looking for more power and want to start with the heads, pull them and get them professionally portred and polished by a reputable machine shop. This will give you some good gains.

Hope that clears up some stuff for you.

[herkyhawki]

Originally Posted by rlith

For the 92-95 Differences are a little more noticeable. Vin W was 195
HP and use CPI..... Other than that the blocks themselves are identicle through all years.

Sorry to get too far off topic, but I want to offer a slight correction here. 92-95 block CASTINGS are the same, but "blocks" as in "shortblocks" are not the same. Most 95's (and all OBD2 95's) have the crankshaft and pistons of a 96+ block. The crankshaft snout is machined to accept crank position sensor (some late 94's also have this crank). The 95+ pistons have thinner rings, and the rings are closer to the top of the piston. If you use a 95+ block, you need a 95+ ECM and year-appropriate Knock sensors to avoid damage to the more delicate piston-ring arrangement. GM moved the ring up to improve emissions by minimizing the amount of air/gas mixture along side of the piston, above the top ring.

[rlith]

I'm not so sure of that... The only difference I've ever noticed between those years is that the timing chain cover portion of the front of the engine has 2 pins whereas later models don't..(pins can be removed)

I have the late 95 motor in my blazer (odbII 1st revision, with the ECM under the hood and side post mount dist)... When my motor blew it was was easy enough to use a 92 cpi motor and moved the following over from the old motor without issue

timing cover (because of the CPS)
reluctor wheel
lower intake (because of the lock pin for the dist)
Dist

(this procedure can be done with later model enginges but you will also have to move the heads over as well)

etc... no issues...

Now I've had the motor disassembled in a 93, 95 and a 98 motor... the pistons are the same... Never notcied what so ever them being thinner on the later years...

[herkyhawki]

Yeah, OK to use a 92 block in a 95, but don't use a 95+ block in a 92 because older ecm + knock sensor will not protect the newer piston rings.
If you check the OEM ring kit part numbers you will find the 95-97 top piston ring is only1.5mm. the older blocks will have a 3mm thick top ring.
If you put heads on a 96+ (and late 95) block, you must use Torque to yeild head bolts and the torque plus angle specs (more accurate). This is because the newer pistons with thinner rings are less tolerant of cylinder wall distortion caused by head bolts. Sure you can just torque 'em all to 75 and it will run, but you are at much greater risk of piston ring damage, especially if you get some detonation.

[rlith]

Originally Posted by herkyhawki

Yeah, OK to use a 92 block in a 95, but don't use a 95+ block in a 92 because older ecm + knock sensor will not protect the newer piston rings.
If you check the OEM ring kit part numbers you will find the 95-97 top piston ring is only1.5mm. the older blocks will have a 3mm thick top ring.
If you put heads on a 96+ (and late 95) block, you must use Torque to yeild head bolts and the torque plus angle specs (more accurate). This is because the newer pistons with thinner rings are less tolerant of cylinder wall distortion caused by head bolts. Sure you can just torque 'em all to 75 and it will run, but you are at much greater risk of piston ring damage, especially if you get some detonation.

Thanx for the info, I'll have to definatly look at that next time I talk to my dealer parts guy...