DuronClocker

I was planning on keeping the 1.94 valves and just having the exhaust seats enlarged for 1.60 valves, but 1.56 is fine with me too. Wonder if I could find those super-lightweight LT4 valves at a decent price and use those. I guess if I could find those valves at decent prices I would just go with 2.00 on the intake as well then.

1.6 rockers it is then.

And the guideplates though, you said yours were narrow. I know the LT1 GMPP guideplates have a tad different spacing (.050" or so) and are supposed to cure that problem on the LT1s. I was only curious as to whether the actual block spacing for the pushrods was different, but I just figured that out because I know the cams are interchangeable. I'll go with the GMPP LT1 guideplates. For installing guideplates on LT1 heads, do I have to have any work done on the heads, or just bolt them under the studs? I know for standard SBC heads, they need some machinework...but most stock SBC heads don't have screw-in studs either.

TraceZ

The LT 1 heads pose more problems for you than you realize.

There are no coolant passages in them for the intake manifold. SBC requires an intake manifold with a thermostat in it for the forward flow cooling to work.

The matching LT1 intake has no coolant passages in it, and no thermostat. What are you going to fasten the upper radiator hose to??

The LT1 heads have a special steam tube that goes to both of them.

The LT1 waterpump, with built in thermostat will not work on your SBC.

The LT1 intake manifold does not have any provisioning for a rear mounted distributor. No hole, no bolt down.

Are you going to build an engine with no distributor and only 1 radiator hose?

It just is not going to work, man.

DuronClocker

Yep, you're right. That's why I have a remote thermostat housing already tapped for the coolant line from each head and to fit the waterneck from the radiator hose, as well as the coolant temp sensor located in the intake on my car.

Yep, and I'm going to use these as coolant ports to connect to the aforementioned remote t-stat. Basically, external coolant crossover.

I'm not going to use the LT1 waterpump. I just bought a "heavy-duty" replacement for my current 305 (will go to 350).

That's not a hard one to fix. Guys have been putting LT1 intakes onto standard SBCs for years now.

This was already answered in the above questions, but in short, no


Now, could somebody please give me this information on the LT1 heads that I asked about in the original post (thanks WS Sick for your responses so far) and not worry about how I'm going to get the LT1 stuff on? I'll make a whole write-up of it when I get the rest of the cash for the remaining parts and get the time to work on it.

96capricemgr

I would go 1.6 to get up into the best of the headflow. All my reading indicates the GMPP guideplates do fit better than aftermarket.
Pushrods are 5/16th I think whatever standard SBC size is and the length is going to depend on your block, the 1.6 should not matter, if it is a factory roller cam block then factory roller length pushrods should be right, if not I don't know what to say other than measure twice buy once. The valves are nothing exotic sizes are standard, not sure if the seats are big enough for 1.6.

On the L98 and ZZ4 heads, they are one and the same and flow 15% less than Vortecs or LT1s, not worth considering for much of anything. My best guess as to why GM would use them on that crate engine, is because people think aluminum is magically better than iron, that engine would make more power with Vortecs. I think it safe to say that a 15% flow increase would offset a 35lbs. weight gain.

TraceZ

I'm impressed. It sounds like you have a handle on things. I'm really interested in seeing the project completed.

I'm sorry if I sounded doubtfull.
Best of luck to you, and please post pictures!

DuronClocker

Most of the research has already been done by tpi_roc over on thirgen.org in one of his threads. I'll have to link to it here next time I pull it up. The LT1 intake stuff can be researched at www.lt1intake.com. Its a great site, and John is a great guy to deal with.

Also, thanks again for the replies so far. It looks as if I'll be buying:
-1.6 roller rockers
-EX-612 springs
-GMPP LT1 guideplates
-Chrome moly pushrods. Haven't decided on 5/16 or 3/8 yet. Probably 5/16 for my use. No extreme seat pressures or anything.

Can't decide on upgrading valves a bit, I'll have to look into some prices. Are valves by "Elgin Industries" any good? I've seen those quite cheap, so I was kind of questionable about them. Anyone know where I can pick up the light-weight LT4 valves?

My only remaining question is on how to prepare the head for the guideplates. Is anything necessary, or do I just loosen the rocker studs, and re-torque them down with the plate in there?

DuronClocker

Wow, the 2.00 LT4 intake valves are $32 each on GMPD and the 1.55 exhaust valves are $27 each. I think that's a bit out of my price range..

96capricemgr

The stock valves are decent, probably not worth replacing them unless looking for every last HP.
Wish I could help on the guideplate thing but I run iron heads and that is what I plan to port, while I do know a bit about the aluminums I am not sure about machining for guideplates, I would think it likely that you would need to take down the stub boss the thickness of the plate. Should be relatively cheap and easy. Since you are doing this much work have you considered 7/16 studs and rockers to match, with that and the guideplates it would be a stout valvetrain, and keep the 5/16ths pushrods they should be plenty strong and with the other upgraded stuff they would become an effective fuse should anything bad happen. By fuse I mean if something oes wrong the cheap pushrod bends before destroying something else.

Lonnie Pavtis

I have a used set of LT4 valves from one of my own projects if interested. 2 of them were damaged due to a connecting rod failure, but the rest appear to be in good condition. Iwas going to use them in a set of Vortec heads, but currently have too many other projects to spend time on them. Send me an e-mail if interested.

DuronClocker

Good call on the 7/16" rocker studs, I didn't realize they were this cheap. ARP rocker arm stud kits are like $30, and I know these already have 7/16 threads in the bottom so its a direct bolt-in.

There's two listings at Jeg's for these though. Part number 070-100-7101 and 070-134-7103

chrism400

This guy is hell-bent on using these LT1 heads. It looks like he has everything figured out. It would be a unique setup and I commend people that try new stuff. It's what Hot Rodding is all about. I made the Vortec suggestion because there are alot more after-market parts available to make life much easier. Not to mention the fact that they flow better than the LT1 head. I know that you can't use a carb on the LT1 intake! I figured you would be running EFI or the new carb intake that Edelbrock is making (not sure about that but I heard a rumor there was one available.) You could always convert an intake I guess. I suggested the L98 head because it looked like you wanted to use aluminum heads for the weight factor and of course the benefit of running .5 more compression. By the way, they have the same combustion chamber size that the LT1 head has which is 58 cc on average. I was just trying to help. Vortec = simplicity.

DuronClocker

LT1 chamber size is typically around 54cc, whereas my 305 heads are 58cc, and L98 (iron) are 64cc. The aluminum L98 heads off the Vettes were 58cc, and flowed just under what the LT1's flow. They would be the ideal heads to use for ease of installation, but again, they are over $500/pair if I could find a set somewhere. Also, looking at some numbers, it looks like the Vortec heads flow very similarly to the LT1 heads, unless there is a huge difference in chamber design or something along those lines.

If I were going to stay with the TPI setup or another standard SBC intake setup, then by all means, I would try to find a pair of the aluminum L98s or even a Vortec setup of some sort. I want the LT1 intake for its flowing/revving abilities and also the fact that its different.

Like I said, I paid $250 shipped for LT1 heads, LT1 intake, and 24# fuel injectors. Shipping was $60, so figure $190 before shipping. For similar results, I could go buy a set of aluminum L98s for $500 plus shipping, and then a miniram setup for another $1200. I'm looking at $1700 for something that I'm paying about $750 for (including all of the small stuff here and there).

That price doesn't include any valvetrain components though. That's just bolting on what I currently have. Another $30 for rocker studs, $90-120 for steel roller rockers, $30 for guideplates, $$$ for valves (if I upgrade them), $110 for springs $60ish for pushrods. Valvetrain stuff is expensive, but I want to make it somewhat bulletproof.

DuronClocker

How would these springs http://cgi.ebay.com/ebaymotors/ws/eB...925426059&rd=1 hold up?

DuronClocker

Is the stock pushrod size 7.200" or 7.800"?

WS Sick

The pushrod I use is the trick-flow TFS-21407200, it is a 7.200 inch rod made of Chromemoly. Its a steal at $84.50 a set from Summit.

You can get the valves from Manley for $11.50 a valve , they have swirl polished heads, chrome stems and an undercut through the port.

I have both blocks on my floor in the garage now ,94 LT1 and a 90 L98, and the valleys look identical excepr for the boss for the Dist plug and the water pump drive in the LT1. Lifter spacing is identical.