Help starting LS transplant

[monzaaddict]

As we all know, 1975 was a transition year for Vegas. The 1975s had the early 1971-73 four-link suspension, but the floor pans of the Monzas and later Vegas along other associated items like larger gas tanks.
I've even read that both shallow coil spring pocket and deep coil spring pocket control arms were in 1975s.

I never thought about these transition issues being a problem during an LS swap.
I'm starting a 75 Vega LS swap myself using the Power by Ace kit. I'm going to have to review the H-body FAQs and refresh my memory.

I would join the facebook groups lsx h body and monza madness. there are a few ls swaps going on using the powerbyace mounts, pan, headers, etc. The new hooker ls s10 cast exhaust manifolds fit good with the powerbyace mounts.

[n8thenetninja]

Do those manifolds clear the stock steering shaft? Or do you have to do the u-joint mod to make them work?

I wish people would stop migrating away from the forums in favor of Facebook... makes it harder for those of us who don’t want the privacy violations to find information, and gradually makes independent forums die off.

[monzaaddict]

one person used them with ace vega ls mounts and it clears the larger Cosworth type steering box if aftermarket coupler is used in place of stock bell shaped coupler. another person used the ace vega style mounts and couldn't get the large stock power steering box to work with the manifolds. It is possible this could have been resolved by slightly repositioning engine and moving steering column in hole on firewall. the box was replaced with a shorter aftermarket power steering box based on smaller vega manual box. He used u joints to route steering shaft around manifold.

[70styleVega]

I'm planning to install my 5.3/turbo 350 into a '75 hatchback that currently has manual steering and manual S10 brakes. I have already purchased a Power by ACE swap kit and Hooker swap manifolds.

Is the photo showing "the 400 series steering box" a typical manual steering setup?
If not, will the stock manual steering shaft coupling clear the Hooker swap manifolds?

[n8thenetninja]

I have a manual steering box. I tried Hooker part # 8502HKR and they did not fit.
https://www.jegs.com/i/Hooker-Headers/5 ... R/10002/-1

I think they probably would have if I had done the U-joint mod that is shown in various places here. The steering shaft is just too close to the rear exhaust ports for most things to fit. I ended up getting the powerbyace headers instead, because I figured I would eventually want headers anyway. (mine is primarily a drag car) They are extremely tight, but mine worked on the drivers side with a mild amount of shimming on the steering gear. The passenger side didn't fit initially due to a tube that was cut the wrong length. Ace eventually replaced the tube, and it fits now, although not as well as I would like. (part of my issues might be due to my individual car and it's hard life before it was resurrected. I have it apart right now, so some of that will probably get addressed as it's reassembled)

If a tight sealing exhaust and ground clearance is important to you (not to mention cost), I would modify the steering shaft and use the manifolds. If you want the better flow and scavenging effect of long tubes, get the headers, but keep in mind that ground clearance won't be great, and the slip fits don't tend to seal all that great.

Last thoughts from me (for what they're worth) is that while a lot of the manifolds available now are vast improvements over their old school cousins, LS engines really like long tubes with big primaries, so if this is a racing application, you're probably going to get the itch for headers eventually. If it's a street car only, you probably won't care that much, and might even enjoy it more with it being quieter and less hassle overall.

[n8thenetninja]

Also, an update on the powerbyace modified oil pan:

I have had it off and on twice, the second time with a good amount of RTV in an attempt to get it to seal. With the RTV, it was tolerable enough to get me through the season, but due to unrelated engine issues, I've taken it apart again, and sent it back to ACE for assessment and hopefully replacement. I have a huge mess under the car and on the exhaust from all the leakage, so the amount lost is not insignificant.

Upon further inspection when I cleaned it up to send back to him, I noticed that it wasn't just warped front to back, but also side to side. 2 or 3 of the bolts don't line up to the block correctly, and the pan has thread marks in the holes from being forced to line up. I also noticed welds on the inside of the pan, which is inconsistent with his claim that the pan is bolted to a flat surface the entire time it's welded.

He says these pans aren't welded in house anymore, so maybe he just needs to find a better fab shop. I don't say any of this to run him out of business of course, only to make everyone aware of what you might be getting, and hopefully to spur better QC from ACE. Good luck everyone! (especially everyone who's got one of those weird 75's. heh)

[monzaaddict]

Just to clarify, hooker offers different ls swap manifolds. The new ls s10 manifolds fit best. Part# 71223026HKR. Other than what is shown I couldn't say what definitively fits but it looks like the standard Vega manual box should fit although the bell coupler might have to be replaced. If needed for clearance, the steering column can be repositioned to upper drivers side of hole where it passes through firewall (red arrow).

[monzaaddict]

I'm planning to install my 5.3/turbo 350 into a '75 hatchback that currently has manual steering and manual S10 brakes. I have already purchased a Power by ACE swap kit and Hooker swap manifolds.

Is the photo showing "the 400 series steering box" a typical manual steering setup?
If not, will the stock manual steering shaft coupling clear the Hooker swap manifolds?

The 400 series steering box is an aftermarket power steering box but the internal gears are based on smaller Vega manual steering box. The guy who owns that car is probably $40k into his build including the cost of the car, and a previous shop that basically stole his money and parts. He hammered the non ac firewall heater core cover for clearance. They should have pulled the whole heater assembly, shortened the cover and spaced assembly back on inside of firewall if needed. As it is I don't think the engine is as far back as it could be on the mounts which are slotted. I think the engine needs to be shimmed to passenger side. The base of steering column needs to be repositioned away from engine at firewall. If all that was done and tight clearance couplers used, I think the column would fit without u joints (possibly even if the stock power steering box were used. But I am just speculating.
As you can see in the drawing below, the Vega manual box is even shorter, so the stock bell coupler might clear.

[70styleVega]

Thanks for the show and tell. That's quite a difference between the smaller Vega box and the 400 box.
The difference in length (shaft comparison as mounted) may help me the most.
I'm definitely going to just assemble what I have, and see where the problems are.

The S10 version of the Hooker swap manifolds were not available when I got mine, so we will see on that too.

Thanks again.

[monzaaddict]

Also, an update on the powerbyace modified oil pan:

I have had it off and on twice, the second time with a good amount of RTV in an attempt to get it to seal. With the RTV, it was tolerable enough to get me through the season, but due to unrelated engine issues, I've taken it apart again, and sent it back to ACE for assessment and hopefully replacement. I have a huge mess under the car and on the exhaust from all the leakage, so the amount lost is not insignificant.

Upon further inspection when I cleaned it up to send back to him, I noticed that it wasn't just warped front to back, but also side to side. 2 or 3 of the bolts don't line up to the block correctly, and the pan has thread marks in the holes from being forced to line up. I also noticed welds on the inside of the pan, which is inconsistent with his claim that the pan is bolted to a flat surface the entire time it's welded.

He says these pans aren't welded in house anymore, so maybe he just needs to find a better fab shop. I don't say any of this to run him out of business of course, only to make everyone aware of what you might be getting, and hopefully to spur better QC from ACE. Good luck everyone! (especially everyone who's got one of those weird 75's. heh)

What happened with this?

[n8thenetninja]

Sorry for the long delay. The short answer is he eventually sent me another pan, and on a completely different engine (I rebuilt a 6.0 to replace the 5.7), it still leaks all over the passenger side, and some on the drivers side. I installed it with the engine out, then when it leaked, I pulled it off while in the car and put RTV on both sides of the gasket, finger tightened it, left it overnight to let the RTV cure, then torqued it. It sill leaks as much as it ever did, and it's worse in the hot weather we've been having lately.

The 5.7l was a stock shortblock with a cam swap. I never had it completely torn down. The 6.0 is a complete rebuild with all new seals, gaskets, rear cover, crank sensor etc. I also noticed when I installed the pan on the engine stand that it didn't lay flat to the block until it was bolted down. That may be an indicator.

This isn't my first (or second) LS engine, and I've never had one leak like this. Seems like the pan is the only common factor.

[monzaaddict]

i should ask, what was the issue that prevented you from using crossmember? Do you want to sell the powerbyace transmission crossmember you couldn't use

I'm starting a 75 Vega LS swap myself using the Power by Ace kit. I'm going to have to review the H-body FAQs and refresh my memory.

~~I bought PowerbyAces - 10505K1 71 - 75 4 cyl to 4.3 Chevy V6 kit w trans mount $ 263.24 and was unable to use his tubular bracketing with the Saginaw 4sp.setup. We went a different route.

[monzaaddict]

ttt