This is going to be a wierd one for you guys. I have a 99 sub that spun a couple of rod bearings. I have a 92 350 tbi motor thats been sitting around for a while. What will be involved in useing the older block in my newer sub? I know the heads will work, I am wondering do I have to use the camshaft from the vortec, more importantly will it fit in the older block? I'm thinking all I got to do is swap the cam, lifters,heads, use the rockers from the vortec heads and the vortec pushrods. I know once i get both motors side by side on engines stands it should be clear what i can and cant do. I just want to save time and get the prep done. Thanks Guys
CK5
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Vortec heads What cam to use?
- Thread starter bigjohn79
- Start date
the vortec motor should be roller while the other is not but you should still be able to use the roller cam in it. you will have to use the cam, lifters, pushrods and rockers from the vortec motor. there is also another piece, not sure what to call it, but it is a metal cage type of piece in the lifter valley used to keep the lifters in line. it has three bolts in the center of the lifter valley. if the 92 motor has the three holes drilled in the lifter valley (which it should) then you should be able to swap the cam and other valve train parts over. make sure to keep them all in order as to which cam lobe the lifters and pushrods go though.
All that stuff should go on without a hitch. But the newer motor has a crank sensor on the timing cover, where the older one doesn't. I've heard that you can swap it over, but never checked into it....I try to stay away from OBDII stuff....
Yeah, I forgot about the crank sensor. I am sure the cranks are the same from like late 60's all the way up, so I should be able to pull the reluctor ring off of the vortec crank and slip it on the older one and just use vortec timing cover. So the pushrods are the same length?( and yes there is the 3 holes in the valley).
pauly383
Daddy383
The journal size increased in 68 ( 400 excluded in 70 , thats one motor with own size ) , but the crank changed in late 85 for the 86 model year to a crank specifically for the one piece main seal block .
Of course there are adapters for any crank into any block .
I do know the early 90's trucks have the vavetrain bolt bosses drilled and tapped , since I have a couple of those sitting in rigs now . Unsure of the crankshaft sensor , I will look harder at my 99 Vortec Sub when I get home .
i think the timing covers a 1 time use also molded in the frt face.
If you're wanting to swap your complete 92 engine in place of your 99 vortec it's not that easy. First off the vortec engines have a completely different arrangement for EGR since thew vortec heads don't use an exhaust crossover in the heads and manifold like the non vortec engines. Easy enough to swap the vortec heads onto the 92 engine. Now unless the 92 engine is drilled and tapped in the front for the cam thrust plate, lifter bore tops machined to accept the lifter bars, and the boss's for the spider tray are there and tapped the cam swap will be impossible. The timing cover on the vortec is differnet than a non vortec engine (should be only 6 bolts holding a plastic cover versus 10 bolts holding a steel cover) so this means any crank sensor there isn't going to work.
Can you swap the plastic cover onto the older engines? My understanding of the plastic cover is that GM simply reduced the number of bolts used, but of the remaining bolts left, they are in the original timing cover bolt pattern. (if that makes sense)
As to the one time use claim, apparently if you are easy on the cover, it can be re-used without ill-effect. I suspect the one-time use comment is just so the cover doesn't fall apart from heat/age after you reinstall it.
As to the one time use claim, apparently if you are easy on the cover, it can be re-used without ill-effect. I suspect the one-time use comment is just so the cover doesn't fall apart from heat/age after you reinstall it.
The bolt pattern is not the same and it cannot be used on the older blocks. I've investigated this years ago.
I know it's the internet, still can't see where the bolt pattern is different though. (and I'm talking solely about the bolt holes, not the depth, sensor, or missing bolts, etc)
http://intertechparts.com/images/cover004.JPG (notice the bolt hole "tabs" are somewhat there where holes should be for earlier)
http://www.flickr.com/photos/scorpiogeek/2172028511/
I've got a complete vortec in my garage, no way I'm going to get time to mess with it soon though.
http://intertechparts.com/images/cover004.JPG (notice the bolt hole "tabs" are somewhat there where holes should be for earlier)
http://www.flickr.com/photos/scorpiogeek/2172028511/
I've got a complete vortec in my garage, no way I'm going to get time to mess with it soon though.
i am sure 4x4 high would know for sure as he builds motors all day for a living. better trust him on this one i think.
The motor is still in the sub, and I have the 92 block on the stand, so I will not be able to tell if the timing cover will swap over. Sounds like it wont and without the cranksensor I am screwed! The point of this swap is because my lower end is junk on the 99. I dont guess there is a way to do it. Oh I wonder if we have a vortec timing cover in stock at work? Iwill check tommorow.
Like I said, it's the internet.
I know I've seen it in print, that's the only reason I asked, and made clear that I wasn't talking about the sensor, solely the bolts.
I suspect it was in some car or engine building magazine that I saw it. Mistakes are made everyday, not implying anyone here has...I'm less likely to trust a magazine than Scott.
pauly383
Daddy383
I wonder if some external crank position sensor could be made to work , like from MSD or the like for triggering their ignition boxes off the front of the motor .
Another thing for googling today , I love learning .
Another thing for googling today , I love learning .
pauly383
Daddy383
well someone in this thread used a normal cover on a vortec block , so maybe the vortec cover will go onto a normal block . And maybe the ring to work with sensor will fit your crank
http://67-72chevytrucks.com/vboard/archive/index.php/t-154413.html
I am not about to strip my Vortec down to verify myself though .
http://67-72chevytrucks.com/vboard/archive/index.php/t-154413.html
I am not about to strip my Vortec down to verify myself though .
!I got the vortec timing cover in today and it bolts up perfectly. There is two unused holes towards the top, like @ 2 and 10 o'clock. I still have to pull the reluctor ring off of the vortec motor to see if it fits on the old one but, I know chevy's and they make parts to interchange(unlike F*RDS). 
The bigger question is...does the cover look like it will seal on the earlier block. I think that was the issue.
Do you mean seal against the block or where the pan and cover meet? The bottom of the timing cover has a lip that goes under the block then the oil pan bolts to the bottom of the block cinching it all together. I will check again and let you know.
