MAXXLIMIT

iTrader: (16)

If a 1st gen sbc has centerbolt valve covers is it a vortec block? is there a way to tell the difference between 1st gen set up and a vortec set up. its in a older car but this is not the org motor. Any help would be great!

ZONES89RS

iTrader: (25)

Center bolt pre 96 heads have 12 intake bolts and the newer 96-98 vortec heads have 8 intake bolts that are straight up and down and have no center intake bolts.

HTH

EL T1

iTrader: (1)

It just means it has 87-99 heads on it. GM changed to the design in 87. They could be anything not necessarily vortec heads. If you can check the face of the head where the brackets bolt up you should see this ^^^ cast into the head. Those are vortecs.

Without looking up the numbers I dont know how to tell a vortec block from another.

ls2firebirdde

look for 69 # heads theres another # but i dont know it off the top of my head

supermouse4

Vortec intakes have eight bolts instead of twelve.

Also, the casting code of the Vortec is three triangles as another poster has said. The valve cover for these heads are centerbolt just as the 87-99 cylinder heads.

Pocket

iTrader: (22)

The vortec block is the same SBC block used in older 1pc RMS vehicles. It came in both 2 bolt main and 4 bolt main versions, usually without the fuel pump hole

Internally, the biggest difference was PM rods. Nothing special about the shortblocks really

moge11

WRONG! they are NOT the SAME block!...almost but not! the old blocks will wear the hell out of the cylinders, vortec blocks rarely come out with a ridge in the bores...
AND....THe timing cover bolt pattern is different....

Pocket

iTrader: (22)

Uhh no, they both have the same casting number as long as they are 1pc RMS

Cyl wear is specific to an engine. Newer engines usually have less wear than older engines for obvious reasons

The plastic timing cover itself is different but interchanges. The bolt pattern is the same for the blocks, just a few holes arent used. They are still tapped for the older tin covers

The main bolt hole difference comes with some of the LO5's being setup for tappet cams. The lifter valley bosses are present but are not drilled. All L98 TPIs, L31's and most of the LO5's are roller blocks

moge11

thats funny....cuz when I went to install this motor I was gonna put an old steel cover on, but the holes didnt line up and two of the holes arent even in the block...guess you havent had them in front of you huh?

Pocket

iTrader: (22)

My GTA has a factory L98 350 TPI block in it. For the 0411 swap, a crank trigger is used. I have to use the plastic timing cover, reluctor ring, nub head bolts and thinner vortec balancer. Either two or four bolt holes were not reused with the new cover, I cant remember which

Vortec timing cover on older SBC

Next, I have a 1990 16' cube van with a LO5. I pulled a L31 from a junkyard and swapped all externals including the timing cover from the LO5 onto the L31 longblock. One difference was the 90' LO5 was a tappet cam so I used the old TPI timing cover. I had all the holes I needed

SBC stuff on a vortec

Not only have I had them in front of me, they are in my driveway

birdmaro

iTrader: (45)

i'd advise against a pissing match with pocket...dude knows his ****.

moge11

I do too!!!

moge11

Its four holes that wont work...so why on earth would you use it? two dont line up and two arent there...

thanks for proving my point...

Pocket

iTrader: (22)

Alright, Ive had enough of this discussion

These are the two bolt holes in question. They are behind the waterpump


The plastic vortec cover on the old TPI block. You can see the difference in cover thickness and the general bulk of the bolt heads. I assume leaving them out was for clearance of the pump, not anything to do with the block


The rest are the same


The L31 longblock with LO5 trim and the TPI cover. The engine is out for rings this time. You can see the bolt behind the water pump is very much IN PLACE WITH A PRE-TAPPED HOLE


The rest are stock


Find a cheaper or easier way to put a LSx friendly crank trigger on a SBC, then tell me an OEM cover which does exactly that is unusable because it skips a few holes, nevermind the outer ridge is quite beefy and doesnt leak a drop...

Thanks for proving you're an idiot

Sup Crunk

moge11

Well, you proved your point... BUT, Im telling you neither of my two blocks have the holes thought..they are both 98 blocks though...maybe yours is of the 96 model.. possibly left overs.. My bad on it being four holes... I was thinking for some reason that the other two were move slightly.. I was wrong.. Have been before...But seriously, mine dont have the holes that yours do...

Pocket

iTrader: (22)

Nothing a tap cant fix

In reality is dont make a bit of difference about it either. The newer plastic cover houses the reluctor ring, but you dont have to use it. Let sleeping dogs lie and keep the plastic cover on there