I recently installed an LS376/515 in to my '64 Skylark. I must say that the combination of Holley and Hooker parts made the swap virtually painless. The Holley oil pan cleared the crossmember and steering linkage with plenty of room to spare. The pan sump sits at least a 1/2" above the crossmember while still holding nearly 6 qts. of oil. The Hooker engine mount brackets combined with GM LS1 motor mounts put the bell housing and transmission in the exact location as it was with the 455. The Hooker headers offer plenty of ground clearance and actually are tucked up above the bottom of the oil pan. The Hooker Blackhearts exhaust sounds great and is true bolt in system for the 64-67 A-body. The exhaust system literally requires no cutting as it engineered to slip over and clamp to the 3" header collectors and out the back, tucked up tight with turndowns at the rear bumper. I went with the carb LS so I could re-use the Holley Terminator system I was using with the 455. All I had to do there was download the Holley EFI software, connect to the ECU, switch ignition type to 58x reluctor and change the firing order. Done.
That's sweet.. One day I'll do a ls swap in something Was thinking about my 67 impala. How did the wiring harness work out What kit did you use
I replaced the original Holley Terminator harness with their Terminator LS 58x harness. That included the cam/crank sensor, coil pack and oil pressure sender connections that are not part of the non-LS harness. As far as the main harness, I replaced the car's original wiring with a Painless 28 circuit system a year ago.
Speedometer is cable driven off the tranny. Still using the Autometer mechanical oil pressure, temp, voltmeter and tach. The LSx harness includes a lead that connects to a traditional tach. I feed the Autometer temp gauge off a fitting in the rear of the passenger side head. The factory LS temp sender in the front drivers side head connects to the ECU. In the future I may switch over to Holley EFI gauges that can be daisy chained and connect directly to the ECU with 1 wire. Even if I do that I'll still keep the mechanical oil pressure gauge hooked up.
Interestingly I just read about a test using a 2000-2005 LM-7 5.3 engine with a few bolt ins but stock internals except a cam swap... this cam gives a 90 HP gain over stock without giving up any low RPM torque... I'm swapping this cam into my truck next week. Quote from the test: Test Motor-Stock 5.3L with springs, truck intake and manual TB. QTP 1 3/4 headers and Holley ECU. Replaced the stock LM7 cam with a Crane 590 lift, 224/232, 115 lsa. Stock cam- 353 hp @ 5200, 384 lb-ft @ 4,300 Crane Cam-442 hp @ 6,200, 412 lb-ft @ 5,000
The transmission is a TKO600. That, hydraulic TOB, Holley EFI and the radiator/fan were the only parts I could carry over from the 455. Total cost for the engine swap was north of $10k. I got the engine from JEGS at a pretty decent discount because it is a 2014 that had been sitting in inventory since then. For the engine I needed an A-body compatible oil pan and headers. New bell housing, flywheel, clutch and pressure plate. LSx harness for the Holley Terminator, new starter and accessory drive. I was able to recoup about half the cost by selling the 455 and other parts, many of which were sold to fellow board members. The motor sounds great and has an awesome idle. I haven't driven it yet because I have to tidy up some wiring and reinstall the dash. That will be finished this weekend, just in time to drop the top and take in the fall weather that finally came here to west central Florida.
I did quite a bit of reading before I did the swap and every article I read said basically the same thing: the LS motors respond very well to a cam swap. I set out trying to find a salvage LS3 and swap in a Comp LSR cam but the LS3's are hard to find and when you do not they are not much less than a new crate version.
My next LS build for my mud truck will be a 6.0 iron block, 4.8 crank, for a large bore short stroke setup... with a GT-45 turbo... will rev to 7500 and should get the wheel speed up on the 44 inch mud hawgs lol.
Here are a few more. I actually don't mind the coil packs. Kills the old school look but maybe down the road I'll conceal them.
I used the same oil pan, motor mounts and headers on my LS swap in my 65 Wagon. As you mentioned, everything fits like it's supposed to. Well designed and well made pieces that save a lot of time and hassle from having to figure things out yourself. -Josh
