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Engine SwapEverything about swapping an engine into your Third Gen.....be it V6, V8, LTX/LSX, crate engine, etc. Pictures, questions, answers, and work logs.
Hello, as the title sez, thats what I'm doing. This project started by almost buying a "built Early 70's Corvette" 350 from a friend of a friend..I dug into it and found out it was really 1983 Buick lesabre 305 with Moroso valvecovers on it. (thank you GM Vintage amnd Compression gauge) I told him to stuff it. Thats why i'm done messing around with used crap.
Anyways I've already read thru most of (not all) of the exhaust header, T56 conversion, engine swap & EFI to carb stickys here. Im not Stephen Hawking so I can't instantly remember every detail of every thread posted on the subject. Don't be too hard on me. Mechanic is not my profession. I'm a Forester in real life.
My car is a 91' 1LE/R7U. I still have a few issues im unsure of. List of parts I purchased is as follows:
Brand new Turn Key ZZ6 crate motor. 405hp/406ft/lbs.
Brand new T56 Magnum PN#19329795. the closer ratio one.
Brand new New GM Bellhousing/cluchkit with hydraulic slave cylinder as the ZZ6 comes set up for auto. PN#19329025 & 19329633
Hawks 3rd gen T56 trans crossmember.
Big Teds Custom Muffler Bearings lol
The last engine swap i did was in late 80s switching out 327s in an old 60s impala lol so i know the basic basics just not the fine details. Below are my plans/issues or lack there of so far. If anyone sees anything glaring that im missing or just plain out to lunch on let me know.
EXHAUST? I have No cat converter on car now and luckily I have no emmisions to worry about. I will just drive my car with open headers to exhaust shop to do whatever they have to do to connect headers to stock ypipe. (which i will get them to convert from a T to an actual Y. I'm not going to bother connecting them myself. Rest of exhaust will have to wait awhile. So im still undecided... Thinking of holley 1&3/4 2055s so or maybe longtubes instead. I dont think my new motor/trans combo will have any header fitment issues that differ from LB9 T5. (that I know of yet) TPI headers have bigger diameters than the carb specific headers. so thinking of tpis with the Hooker stove ,flextube & clamps for the 1 and 3/4 system.
Fuel I see people have have quite a few ways of doing this....I plan on just running an 8psi inline electric and suck thru original in tank pump. Mechanic at GM dealer told me i don't have to drop tank and remove or gut original in tank. The pump in my tank has a swinging fuel pickup for racing (part of the R7U package). I am confused however about the return to tank line.....Leave open to not deadhead pump or close off to maintain enough pressure to get to carb. I heard about getting a CTS-V fuel filter that has a return to tank outlet using the in tank pump with that and a regulator? BTW the motor does have a mech fuel pump on it.
Driveline Car has 3:42 rearend with locker. A few years ago i upgraded the axles with beefier American Axle units. 28spline. I won't be dragracing or anything so I hope it holds up. The T56 RATIOS basically give me a little taller 1st gear than stock, 5th is almost same as WCT5 5th gear. 6th is 0.63. Sounds too tall if the 305 was behind it but ZZ6 should be ok with it i hope? I might eventually order that hawks new 8.8 rearend if mine does not hold up. My stock driveshaft is aluminum (more R7U goodies) but the T56 is longer so I guess im going to have to order a new shaft or cut mine. (Rather get new one as I will be saving all the original parts to retain sales value of car in case that day ever comes.)
I know ill have to cut the top of trans tunnel back 2 inches for new trans to fit. T56 has a 2 position shifter plate included with a 3rd position built into transmission so I'm hoping that between the 3 positions, one of them will place the shifter where it should be in the console?
Random stupid questions:
Will the weight reduction of new motor (aluminum heads) effect the ride height of the front of car? I don't think it will?
I don't need the AC pump that comes with the ZZ6 so was just going to stick the AC delete part of the LB9 serpentine on to the ZZ6? Looks like a straight across switch am I right?
Wandering about tossing the ZZ6 regular open element airfilter in favor of a cold air duct like the type they use for blow thru carb turbos and connect it to stock intake duct over the rad? Will that stock dual air filter duct flow enough helium to not choke back the new 400hp motor? I'm thinking probably....
The tranny should be arriving tomorrow and the motor with rest of parts on October 3rd. Hawks is supposed to give a list of some other things i might need. Should get that tomorrow. Any suggestions, comments would be cool. I'll post pics as it happens.
Thanks a bunch guys...
Exhaust - I love my Dyno Don's headers. The Y pipe fits in the stock location. While you are not restricted by emissions, this might present fewer headaches for install.
Fuel pump - skip the mechanical pump, replace the in-tank pump with an 8psi TBI model. Or, you might need to stick with a TPI/EFI 45+ psi pump just to get enough volume for 400+/-ish HP. Either way, plumb it to a fuel pressure regulator (FPR) to get it down to carb appropriate pressure, and use the return line for the excess fuel.
T56 - (Nevermind. It looks like you have this covered with GM Performance Parts I didn't know they now offer. Looks comparable to the QuickTime scatter shield.) The aftermarket T56 are "LSx" style, long input shaft. Did you get the proper bell housing/adapter to bolt it up to your SBC/ZZ6? ... See here, here, or use a Quick Time Bellhousing RM-6023. Or, while you don't need the whole kit, here is a company (redirected from an old Kiesler link) that offers T56 swap packages... you would just be interested in the bell, flywheel, clutch, hydraulic (slave) parts.
Weight - whatever the engine is lighter, the trans is heavier than the T5. Although the weight moving lower and further back may have a minor effect.
Wow, this is going to be a nice build. Definitely staying tuned!
Hopefully but there will be issues..... I'm sure this motor will not even fit under my stock hood with it's single plane manifold and 770holley. Judging by the press photos of motor, it's fairly tall. So maybe a 2.4 inch tall open element with drop pan and only 9 to 10 inch diameter? Smaller diameter might help because this manifold places carb parallel with motor. (doesn't tilt it ahead to levelas far as i can tell) I know using smaller than 14/3inch setup is not optimal. Maybe a low profile carb hat but that reduces flow to around 675cfm. Possibly a 70" L-T1 repro air cleaner, I heard might work. If not then I guess cowl hood. Who knows, I might luck out but I doubt it.
Exhaust - I love my Dyno Don's headers. The Y pipe fits in the stock location. While you are not restricted by emissions, this might present fewer headaches for install.
Fuel pump - skip the mechanical pump, replace the in-tank pump with an 8psi TBI model. Or, you might need to stick with a TPI/EFI 45+ psi pump just to get enough volume for 400+/-ish HP. Either way, plumb it to a fuel pressure regulator (FPR) to get it down to carb appropriate pressure, and use the return line for the excess fuel.
T56 - (Nevermind. It looks like you have this covered with GM Performance Parts I didn't know they now offer. Looks comparable to the QuickTime scatter shield.) The aftermarket T56 are "LSx" style, long input shaft. Did you get the proper bell housing/adapter to bolt it up to your SBC/ZZ6? ... See here, here, or use a Quick Time Bellhousing RM-6023. Or, while you don't need the whole kit, here is a company (redirected from an old Kiesler link) that offers T56 swap packages... you would just be interested in the bell, flywheel, clutch, hydraulic (slave) parts.
Weight - whatever the engine is lighter, the trans is heavier than the T5. Although the weight moving lower and further back may have a minor effect.
Cool project!
Thank you,
The y pipe i now have is supposed to tie in these used headers to stock single cat inlet location. We will see.
Yes I have the proper GM performance kit made specifically to connect their 6 speed to 350 and its coming with the motor.
Mechanic at GM who's done a few FI to carb swaps told me to do pretty much what you said. He said it will be ok to suck thru the stock intank pump with swinging pick up.
So the motor and trans are in. My trans has no torque arm mount. Is there an aftermarket relocation kit or something that will work? I'm finding things for turbo 400s but no t56.
So I talked to spohn this morning and they told me that torque arm assembly/crossmember kit won't work, they don't make one and no one makes anything to attach a torque arm to my T56. It looks to me like it might work though. I would have to get one in my hands to know for sure i guess. The hawks crossmember i have already did not quite fit. The holes had to be oblonged a bit to make them match up. they also sent a bracket to attach the torque arm to t56 mount holes which mine doesnt have of course. lol Any ideas?
The 1993-2002 T-56 tail provides the trans mount, which will not work for you: Founders
Thank you, Yes I'm looking for one that attaches to crossmember or body not the trans itself obviously if it has no holes. So far Spohn tells me none of their xmember attached torc arm assemblies will work or anybody elses which to me means the rest of the aftermarket. Hawks sent me stuff to attach the cars original Torc Arm to a trans torc arm mount when I thought i was going to get a new tourque arm in the T56 swap kit they sent. I sent them the pic above about 2weeks ago and have got no response. That sinister arm looks possible. The bmr site only has 4th gen ones and the one 3rd gen they have is unadjustable and too long .
Maybe this one is possible? It's a different part # than the link Bottledz28 posted. His was for "93-97Fbodyt56". This is for a "Tremec Aftermarket T56" http://www.hawksmotorsports.com/cama...-transmission/
It looks like it will work even though spohn kid said nothing will. Honestly I think the kid at spohn was more interested in going for lunch than talking to me. Hopefully I hear from Hawks.
So i ordered the Sinister torque arm and crossmember to mount it to and the sub frame connectors. Just showed up so I'm hoping it works ok.
New sinister torque arm & frame braces mounted. So I guess if u want a brand new Chevy performance t56 magnum in 3rd gen u need a setup like this if you want to keep the magnum tail housing.
I'm all Done. I just need to time it and adjust carb. Also bolt exhaust to headers. Can't post video from my phone it seems. I'll try to do it from computer later. Sorry
09-19-2016, 09:11 PM
