I have a few questions on an upcoming engine swap I'd like to get answered. I got a sweet deal on a rebuilt LO5 thats a 355 with forged pistons. The gentleman I bought the engine from also had the 193 heads rebuilt. I did some research and I recognize that the 193 heads flow like crap. I currently have my LB9 engine with the peanut cam. The heads on the LB9 need to be rebuilt badly since they smoke (bad seats). My first question is which flow worse, 1987 LB9 heads or the 193's?
Also the block has the provisionnings for the hydraulic cam and lifters. The only problem is that the "towers" where the spider plate bolts on to don't have the holes drilled. Is this something I should do? I have a drill and the taps to do it. I was just wondering if I should let a machine shop do it. From what I've read, the spider plate only holds the wishbones in place so its not a "precisely machined" part of the block...?
Another thing, I plan on turboing this motor, and I'm going to get a new timing chain, is the one from the autoparts store sufficient or should I get some sort of special, high performance expensive timing chain?
Lastly, I need to get a cheap gasket set. There are plenty of good deals on ebay, but most of them say the gasket set is only good for up to year 1979, why is this? Is it only for the rear main seal? I'd like to know if I can use one of these kits for the main pieces like intake gasket, head gaskets, oil pan gasket, timing chain cover gasket, should there be a problem? Thank you for reading my long post...

 

79 was about when the dipstick location changed. 86-up have a 1pc rear main seal and a one piece rubber oil pan gasket. Head gaskets and intake gaskets should be the same, but the oil pan gasket, and RMS won't work on a later block.

 

Recently rebuilt heads are always better than worn out heads. If they bother you that much, grab some pro-comp, L98 or L98 vette heads with less miles

Drilling the spider tray bolt holes is not too critical. Just be clean about the shavings and dont get excessive in the depth (cam under there). The main issue is having the bosses cast in the block to begin with. You may need to change timing cover, but you're robbing your old LB9 anyways, whats another piece

Any common HD timing chain set should fit the bill, even single rollers

 

thanks for the replies guys, that really helps me out. I knew about the rear main seal and I wasn't 100% sure about the oil pan gaskets. In a few months I do plan on removing the heads for some performance heads. Right now my main focus is just to get my car running again...

 

If it doesn't have the spider bolt holes drilled, it's probably not machined for the dogbones either.

Rebuilt heads are better than worn out heads, unless the rebuilt heads are 70s smoggers or swirl ports. Fortunately, it's real cheap to freshen up your LB9s anyway.

 

The block has been machined for the dogbones (it has the indentions on the bores) and the holes for the cam retaining plate have been drilled. So its just the spider bolt holes that need to be done. I'm not 100% sure on the history of the block. The older gentleman I got it from had it sent out and machined. All he knows is that is from a late 80's early 90's truck. He was going to put it in his beautiful 1932 Cadillac but he said his 1932 engine just kept on running so he stayed with it. I thought I was just going to get a regular 350 L03. I paid $600. He said he had over $1200 in machine work alone but just wanted to clean out his garage. Once I got home, I checked out the part numbers and it has forged pistons that are bored over .030 (The pistons have "030" stamped on them along with "F" at the end of the part number for forged), the heads are the 193 castings, but they are rebuilt with new everything (seals, springs, valves, etc)... I plan to reuse everything from the LB9 that swaps, which is just the oil pan and intake. I've had a LT1 cam lying around I'm going to throw in there since I'm sure the LB9 peanut cam is worse. Do you guys think I'll be ok running a LB9 computer and injectors with the fuel pressure bumped up a bit? I plan on getting a 350 knock sensor from the jk...Another thing, since I'm using the 305 flexplate, do I use the 305 harmonic balancer or do I use the 350 harmonic balancer (came with it)?

 

Flexplate and balancer will work no problem. Those only become an issue when you change from internal to external balancing

It will like the LT1 cam, why must the pan be swapped? Older SBCs seem pretty generic in the pan area

With a decent tune, the 305 parts will work fine. Injectors may be close to maxed though

 

I figured the pan would be swapped since I wasn't sure on the interchangeability of the truck parts. I guess I'm used to the LSx stuff where almost nothing interchanges. I guess I'll compare the 2 oil pans. I'm going to take the opportunity to tap the oil pan for oil return line for the turbo too... I also have 28lb injectors I was saving for the turbo swap. I think I will try to get this running. Once it is running, I'll "fine tune" whatever I can, then I'll bolt on the turbo...

 

I have another question, do you guys think I should use the LB9 pushrods and lifters? I don't have any other ones, but I can go the junkyard and find a caprice with a LT1 and take those? Eventually (couple months) I do plan on replacing those with new lifters and rods aswell as new heads and cam.
Another question is, the fellow I had bought the engine from had it sitting in his garage for months. I didn't get any paperwork so I'm not sure of the build date, but I'd like to try to rotate the crank to be sure everything is turning and working fine. It will be rotated by hand. Do you guys think I should cover the inside walls of the cylinders with motor oil? On some of the cylinders you can still see the oil between the cylinder and the piston, but other cylinders look dry? Should I squirt oil all over the bottom end too? Thanks guys...

 

If the Lifters are in good shape you can reuse them. Ditto for the pushrods, if you happen to need the same size once you get it all together.

 

ok cool. The car had no valvetrain problem before, so I guess they should be ok to use...for now. The engine had about 146,xxx mi on it. One more thing, what goes on first, the oil pan or the timing chain cover? I'm sure I'll find out when I take apart the LB9, but I just want to be sure...

 

bump

 

Timing chain cover goes on first.

 

thanks

 

another quick question. Do you guys think I will be able to run the engine "ok" with the stock LB9 computer and 305 knock sensor and 305 injectors (with the fuel pressure bumped up)? I just need this to drive for a few weeks while I start my new job, as the money starts coming in, so will the appropriate parts...

 

so should I use the 305 harmonic balancer or the 350 balancer? I have both and the 350 one is considerably bigger than the 305 one. I'll be using the 305 flexplate...

 

Whichever one works with the comb on your timing cover.

 

well, I have both timing covers. The 350 timing cover and balancer are nicer since they were machine cleaned. I even painted the 350 cover black (but didn't install the seal yet for this reason). The 305 cover and balancer are all nasty and oily/grimey since the front main did start leaking. I just wanted to make sure it wasn't a matter of "proper balancing". If I can get the LB9 cover clean enough, I'll use it. Since the LB9 cover has the timing tab that indicates retard and advance timing marks. The LO5 cover only indicates retard timing...