When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
New Hooker SN95 Mustang LS swap system preview thread
Hey guys. I've begun the development of this new Hooker LS swap system application and have created this thread as the collection point for all relative technical information that will be associated with it. I've only had a week to spent with the initial development car so far (98 GT), but I can already see that opportunities exist to improve the state of things as it relates to optimized fitment and compatibility with this application. Feel free to ask any questions you may have throughout the process. Working on this car this past week has me feeling nostalgic for my years of working at Bassani.
Explain where Hooker comes into this and specify what info you want from SN95 swappers.
Thanks for posting. Hooker/Holley will be coming into the development of this LS swap application with the determination to fix design shortcomings/limitations that exist with currently available components and to accomplish that objective in the same full-system manner that we've used on all our applications. If you are not familiar with the scope of our systems, they include an oil pan, engine mounts, transmission crossmember(s), exhaust manifolds, headers and 2.5" and 3" exhaust systems that all work together in a plug-n-play manner. I will make note of any comments/feedback provided to me by members here and allow the information to influence my development activities where it makes sense to do so. If you SN95 swappers have run into an issue that was particularly troublesome and/or expensive to resolve, I would like to hear about it.
Ok, one issue most Fox and SN95 swappers have had is getting the engine/trans to sit low enough to get the trans to fit in the tunnel and have a little clearance around a T56 so it's not in contact with the underside of the tunnel. I had some issues with this and remedied it with 2 things: .375" aluminum flat stock plates between the K member and body, 2: Modified 4.6 MOD. mounts to bolt right to the block and not have to use adaptor plates (UPR) together I saved .625" of engine height, motor sits damn near level and trans has clearance without "hammer massage" as some do. I know this will vary from ea. K member manufacture, I used a QA1.
Another part of this engine/trans. mounting and leveling is the rear cross member, I used a Sheffler's and cut and re welded the trans mount flange to get the angle I was looking for. I mocked it up with an empty t56 case, inserted different pieces of flat stock to put at the height that would work and leave some top of the trans clearance to tunnel.
Yes, I've been investigating these same deficiencies over the last week and can tell you that one single fore/aft engine position will not provide optimized LS engine fitment in an SN95 Mustang for all transmissions that can feasibly be used...this was also found to be true with the 64-67 GM A-body swap system applications I just completed which ended up with the offering of two distinct engine bracket sets to accomodate all transmissions in a bolt-in fashion. The initial investigative mock-up phase is being conducted with the stock K-member to ensure a base reference to stock geometry is established so selection of an aftermarket K-member to recommend can be properly carried out. I can tell you that the use of 1/4" plate adapter plates with the stock 4.6 mounts will allow the LS engine/trans centerline to be placed at the exact same height and inclination angle (on the factory K-member) as the stock 4.6 engine, but will not allow the optimized installation of any transmission other than a TH350,TH400 or Powerglide in the typical fore/aft orientation that you've used (aligning the front holes of the 4.6 mounts with the front two mount holes on the LS block). That position locates the bellhousing mating plane of an LS engine almost exactly 1" further back in the car than the stock location of the 4.6 bellhousing mating plane, which will not allow a 4L60-70 or T56 transmission to be raised up into the tunnel without major interference between the their bellhousings and the firewall/tunnel interface. The solution to this issue is to move the engine/trans mating plane back to the stock 4.6 location without further raising the engine, which I've figured out how to do. I've carried this all the way out to a full mock-up with the 4L60 only at this point and will do a full evaluation with the T56 starting on Monday; I'm also suspecting that the more forward location will also provide improved alignment of the T56 shifter with the stock console as it usually does with other applications and will be sure to report those findings as well. For those installing any one of the less fitment challenged transmissions that want to retain that 1" set back you have, they will be able to do that with this mount set-up by drilling some holes in the K-member to allow moving the engine back. Another benefit to using the stock 4.6 eng/trans mating plane location is that the stock trans crossmember can be used (with an inexpensive adapter) to install a TH350, TH400, Powerglide or 4L60-4L70 transmission.
I installed a LQ9 in my 96 Stang and used the UPR adapter plates which are similar to the pics above and my engine is too high up, which drive the th400 too high up also. But despite that, I got the factory hood to shut using a truck intake and factory K. I'd like to see some engine mounts that drop the engine lower in the K, but I u/s that would be difficult to design for give the different K and pan configs.
Yes, the location of the motor/trans and the T56 shifter location was another issue as I had to cut and trim the rear portion of the opening some. I am in the process of making a shifter cover/lower console right now. I don't think there's any way you get an LS and T56 in the stock shifter (T5) location, there's 4-1/2" or so difference so there will be some modification, it's unavoidable. Empty case mock up shows where your shifter could end up when using 4.6 motor mounts front holes.
I installed a LQ9 in my 96 Stang and used the UPR adapter plates which are similar to the pics above and my engine is too high up, which drive the th400 too high up also. But despite that, I got the factory hood to shut using a truck intake and factory K. I'd like to see some engine mounts that drop the engine lower in the K, but I u/s that would be difficult to design for give the different K and pan configs.
Thanks for stepping in with your post, I appreciate you making the effort to do so. Since your swap is currently based around the use of the UPR swap plates, stock K-member and a TH400, I will be able to post relative comparative data and photos that yourself and others might find valuable. I started the mock-up process with the same adapter plates last week and quickly realized that fitment issues with particular transmissions would present themselves due to their design geometry. The two problems I'm referencing are the relocation of the 4.6 mod engine eng/trans mating plane 1" further back in the car and the diagonal height positioning of the mounts on the plates, which causes the user to have to grind off the indexing buttons on the bottom of the mounts in order for them to sit flat against the K-member mounting surfaces; the geometry of the plates I've devised corrects both of these issues as the holes for attaching the mounts to the plates are completely divorced from the holes that attach the plates to the engine block. The difficulty with maintaining the eng/trans mating plane in the stock 4.6 mod motor location is in obtaining clearance between the K-member and the oil pan (as you know) and that's were the design geometry of the Holley 302-2 oil pan comes to the rescue to resolve. I will be mocking-up the TH400 in the car this week also, so I invite you to check back in to see the results acheived and share your thoughts.
Yes, the location of the motor/trans and the T56 shifter location was another issue as I had to cut and trim the rear portion of the opening some. I am in the process of making a shifter cover/lower console right now. I don't think there's any way you get an LS and T56 in the stock shifter (T5) location, there's 4-1/2" or so difference so there will be some modification, it's unavoidable. Empty case mock up shows where your shifter could end up when using 4.6 motor mounts front holes.
That's a good shot angle that I can replicate following my T56 mock-up. Yes, the 4th-gen F-body T56 is not a prime swap candidate in this application with regards to shifter compatibility with the stock console; the T56 Magnum is far better suited by this measure.
I just completed the T56 mock-up on the stock 4.6 K-member in our 1998 GT and things went very well with the eng/trans mating plane located in the stock 4.6 engine location. I was able to achieve the exact same engine crankshaft/transmission output shaft inclination height and angle(confirmed with both locating fixtures and a digital angle meter)as that of the stock 4.6 engine. At that position, one cap screw on the inspection cover on top of the trans was barely kissing the underside of the tunnel...a couple of blows with my favorite hammer would provide all the clearance I would need to be comfortable moving forward with the install. I'm posting the relative photos here to assist the building of the knowledge base of this thread. 64 Post, this info should be valuable to anyone running the QA1 subframe as you are as you'll be able to confirm the comparative fore-aft placement of your eng/trans compared to someone using the stock K-member and the Hooker engine brackets that will come out of this effort...I pulled a tape measurement from the shifter opening edge to the front of the T56 shifter housing to provide an easy reference for you to duplicate.
Yes, offset, as was the 5.0 when it was in there. I believe they did this for steering shaft clearance. The 8.8 pinion flange seems dead center to the car so I gave up trying to figure that puzzle out. Todd, it looks like your set up is about an inch forward more so than mine.
Yes, offset, as was the 5.0 when it was in there. I believe they did this for steering shaft clearance. The 8.8 pinion flange seems dead center to the car so I gave up trying to figure that puzzle out. Todd, it looks like your set up is about an inch forward more so than mine.
There's few factory cars that are not configured with a passenger side engine bias and the engine being offset from the pinion is not a problem as long as their centerlines are parallel and not so far apart that it creates excessive U-joint working angles. Yes, if you used the UPR swap plates and your K-member maintains the stock engine mount bolt locations, then the bellhousing mating plane of your LS engine is set-back 1" from the stock 4.6 bellhousing mating plane position. This can easily be confirmed by measuring the distance from the bellhousing mating planes of both engines to the front two engine mount boss holes; you will find that the holes on the LS block are almost exactly 1" further away from the bellhousing mating plane. Placing the engine in that location greatly complicates fitment of many transmissions guys are wanting to install in this swap.
I successfully made it through the mock-ups of the T56, TH400, 4L60-4L70 and 4L80 transmissions this week; the TH350, Powerglide and TKO mock-ups will take place next week and will allow the engine mounts and crossmembers to transition to the CAD phase of development.
"Yes, if you used the UPR swap plates and your K-member maintains the stock engine mount bolt locations, then the bellhousing mating plane of your LS engine is set-back 1" from the stock 4.6 bellhousing mating plane position. This can easily be confirmed by measuring the distance from the bell housing mating planes of both engines"
Yes, complicated more than it needed to be.
No, didn't use UPR plates because of engine height issue.
The extra motor set back can help the car transfer weight on launches but that's about it.
Todd, so you are making a dedicated motor mount and cross member that will A: work with stock k member. B: bolt directly to an LS block putting the parting line at the 4.6 location and it will use what headers again?
"Yes, if you used the UPR swap plates and your K-member maintains the stock engine mount bolt locations, then the bellhousing mating plane of your LS engine is set-back 1" from the stock 4.6 bellhousing mating plane position. This can easily be confirmed by measuring the distance from the bell housing mating planes of both engines"
Yes, complicated more than it needed to be.
No, didn't use UPR plates because of engine height issue.
The extra motor set back can help the car transfer weight on launches but that's about it.
Yes, there is a theoretical possibility of benefiting from further set-back of the engine back as you said, but unless someone were to validate the track results of the same LS engine installed with its engine/trans mating plane in both the stock 4.6 and 1" setback locations, the effectiveness of a discrete 1" set-back is unproven and brings with it a multitude of installation/fitment issues as I've discovered over the last week and a half.
If the car doesn't show a measurable, qualitative improvement in launch characteristics until two or three inches of setback is used, then there is no point in setting it back only 1" in my opinion. If it did show an improvement at 1" then you would have a tested, justifiable reason to set it up at that position. Until someone goes through the expense of such testing, I don't see the value myself, but others may.
Interestingly enough, I've not come across a single instance of an SN95 Mustang owner moving their stock 4.6L engine and trans back an inch to improve the weight distribution/transfer of their car, or seen anybody beat up on GM for moving the engine/trans mating plane forward in 4th-gen F-bodies (by 5/8")when they started putting LS engines in them to replace the LT1/LT4.
Todd, so you are making a dedicated motor mount and cross member that will A: work with stock k member. B: bolt directly to an LS block putting the parting line at the 4.6 location and it will use what headers again?
Yes, that is correct. Everything is being developed to work with the geometry of stock K-member and the stock 4.6 engine/trans mating plane location. In order to allow this, the use of the Holley 302-2 pan will be required to clear the K-member at the right front corner of the sump. There may be other pans that will work also, but I know for sure the F-body pan will not.
I will be developing new long-tube headers as part of this swap system, as well as transmission crossmembers and 2.5" and 3" full exhaust systems.
07-22-2016, 06:16 PM
New Hooker SN95 Mustang LS swap system preview thread 
