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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. New guy with my first 3rd gen, heck my first GM vehicle actually. I am swapping a 1984 corvette 350 into my 1984 trans am. My trans am has a locked up 305 h.o. Previous owner says a spun bearing, I have not had it apart to look, but the oil pan had more gasoline in it than oil. yikes. I'll mess with it later after my engine stand is free. Might rebuild it and drop in a truck.
I bought a complete 1984 corvette engine for $400 that I will be swapping in over the winter along with other work to the car. I have a Edelbrock 2701 intake for it and 1406 carb. I will get ceramic coated headers(shiny ones lol) a free flow exhaust and maybe some 1.6 rockers. Not trying to build a race car, just something fun to drive in the summer.
Anyway After I got the 305 out looking at the oil pans they are fairly different, which is not really unexpected. Any one know if the corvette one will clear the K member? I will find out when I go to drop the engine in, but that won't be for a couple months. Pretty sure I could use the 305 pan, but I'd rather use the corvette pan if I can. -Edit- I had searched before I posted but did some more after and found my answer. I'll need to use the 305 oil pan. I'll pick up a new oil pump and pickup and clean out the 305 pan.
Last edited by MadAtComputer; 12-13-2023 at 01:39 PM.
Congrats on both the car and the engine. I installed '84 vette engine into my '82 about 30 years ago: in addition to using standard pan and pickup,had to make some minor modifications to the windage tray you will find on the 'vette engine.While the pan is off,check the little plastic collar on the oil pump shaft and also worthwhile to check the upper timing sprocket as GM was still using the nylon tooth sprocket in '84-( the nylon tooth ring shrinks with age and cracks off in sections) Also use 1 piece pan gasket going back together. One weakness of these "L83' engines is the #'624 heads: mid-1970s style 76cc chamber and prone to cracks-both between the valves and the EGR/heat riser "y" that is in the water jacket-cracks will allow oxygen into the cooling system and you will have rusty coolant in no time...I had the rust y coolant problem and replacing '624s with a set of Dart iron heads fixed that problem. TRW forged flattop pistons on the L83
Thank you very much for the info I did not know about the nylon parts at all. I will replace them with modern ones. Current plan is to buy a melling m55 oil pump, the drive shaft for it that eliminates the nylon bushing, the correct pickup for the original 305 oil pan, one piece felpro pan gasket and a melling double roller timing chain.
Hopefully the heads are alright for now. I could probably buy a set of reconditioned factory heads if needed after saving for a while, but aftermarket would be out of reach.
Last edited by MadAtComputer; 12-16-2023 at 01:34 AM.
What do you know and what do you not know about the Vette engine, I would be asking myself these questions if I were you.
Esp. if I did not see the engine running a.k.a..knowing the provenance of the engine...
If not best take the time to either go completely over the engine yourself or, if you need to involve a third party ?
A trusted mechanic or shop would probably save money time heartache yadda yadda. I know what I am talking about. Bought my
80s IROC with a blown engine. Engine removed in my backyard. Rebuilt by VOSS Racing Technologies. Engine reinstalled in my
backyard / transmission rebuilt + servos 1st and 2nd, in Jacksonville FL in all also in backyard. Therefore with confidence I can recommend you don't
want to have too many re-do's my brutha !
What do you know and what do you not know about the Vette engine, I would be asking myself these questions if I were you.
Esp. if I did not see the engine running a.k.a..knowing the provenance of the engine...
If not best take the time to either go completely over the engine yourself or, if you need to involve a third party ?
A trusted mechanic or shop would probably save money time heartache yadda yadda. I know what I am talking about. Bought my
80s IROC with a blown engine. Engine removed in my backyard. Rebuilt by VOSS Racing Technologies. Engine reinstalled in my
backyard / transmission rebuilt + servos 1st and 2nd, in Jacksonville FL in all also in backyard. Therefore with confidence I can recommend you don't
want to have too many re-do's my brutha !
Story on engine is that it was a spare bought from a wrecked 84 c4 by a late husband for wife's 84 c4 with a 4+3. Bought from the widow for $400 along with the engine stand it was on. The guy hoarded parts and tools, the shop it was stored in was stuffed full. Engine turns over fully. Both throttle bodies are spotless, I have had the valve covers off. was clean, no sludge or corrosion. I will be pulling the pan within the next couple weeks(working on garage currently) so I will see what the bottom end looks like and get ready for new oil pump, pickup, driveshaft pan ect. But yeah basically as far as I really know its a paperweight. It's what I could afford.
I live on a very tight budget, otherwise I'd have bought a proper crate engine. It would take me a couple years to save 4 grand though.
Originally Posted by Tom 400 CFI
Or used Vortec heads and a "Vortec" style intake. Cheap and make a big power increase over the stock 'Vette heads.
Sadly before I knew about the possible cylinder head issues I had already bought a new intake maifold, hardware, gaskets ect for the pre vortec heads. crap.
I borrowed an engine stand from a friend for the old 305 so I can get the pan and engine mounts off it. and so i could move it when needed.
Last edited by MadAtComputer; 12-17-2023 at 10:02 PM.
Sounds promising, so far. You can also put your 305's intake, carb and non-ECS distributor onto the 350, check the oil, then fire it up on the stand or floor just to hear it and see how it sounds before doing the labor of putting it in.
I have been thinking of building an engine test stand. hmm. I'll need a distributor though the original one to the car is controlled by the ecm, or at least appears to be a non standard HEI to me.
We are installing a natural gas furnace in the garage and working on getting more storage for parts/supplies setup. Once that is done I can get back to my car
Oh when I do the oil pump and pickup is one of those copper gaskets for the pump really as great some folks make it out to be?
You don't need a stand. You can set it on the ground w/a ~4"x4" block of cribbing (or two 2/4's) under the front part of the oil pan, and fire it up that way. I've done it w/the small block 400 I put in my Trans Am, decades ago. Blew one of my friends mind! "You can't do that!!"......vrooooOOOMMMMmmmm...la la la la la la la la la. The face was priceless.
OR you can put stand-off's and longer bolts on your engine stand, and put a flex plate on it and start it on the stand. I haven't done that, but would if the situation warranted.
My engine stand has built in stand offs that look like they may clear the flex plate. I did take the one off the 305 and it's in good shape. I'll see if it will fit when i get to it.
The 305 has what looks like a new starter and alternator. A retired mechanic I know works part time at auto zone so I'll go in on a day he is there and have him test em.
I did a tiny bit of work on it today, but man was it cold in the garage. I got the engine mounts off the old engine and removed the hvac fan. The previous owner hacked the a/c out and it's missing pretty much everything. Plan is to get one of the a/c delete panels not the complete block off so that I can retain heat in case i end up driving it in cold weather for whatever reason.
My engine stand has built in stand offs that look like they may clear the flex plate. I did take the one off the 305 and it's in good shape. I'll see if it will fit when i get to it.
It'll fit; they're both neutral balanced, 2 pc seal engines.
swapping engines in a thirdgen is so easy the car is the test stand When you install the 3 torque converter bolts,just snug them down,rotate engine through complete turn,the do final tighten.
What material distributor gear is the correct one for the 84 corvette engine? Looking at some distributors since i do not have a non computer controlled GM one.
What material distributor gear is the correct one for the 84 corvette engine? Looking at some distributors since i do not have a non computer controlled GM one.
Doesn't really answer the question but whether you have a flat tappet cam vs roller will dictate which distributor gear material you get.
I have a new melling m55 oil pump, pick up, drive shaft, install tool, melling double roller timing chain and install tools, ceramic coated summit racing headers and a good bit of other stuff ordered. I was able to sell some stuff I had for sale for several months
Got the 305 oil pan off and mostly degreased. there was a broken off piece of aftermarket dip stick in it. some surface rust on the outside that will clean up well. I'll paint it after. Will probably stick with black.
Last edited by MadAtComputer; 12-29-2023 at 02:18 PM.
I had to get rid of the windage tray entirely. The studs for it hit the trans am oil pan baffle. I used three of the mains bolts from the original 305 to replace the studs.
melling double roller timing chain fit without issue as did a melling m55 oil pump, heavy duty drive shaft and a melling oil pickup meant for the trans am. I set it to the same height as the original after driving it in half way then bottomed it out. it dose not move at all after driving it all the way in. Both me and my dad saw no need to have it welded. I used the $17 proform oil pickup driver. it worked great.
cleaned, rust converted and painted the k member and core support. waiting on a summit order with the rest of what I need to drop the engine in. We are currently swapping the rear end in my dads 96 trans am so will be a bit before I have room the drop the engine in.
Edit parts came in. Pretty much ready to drop it in other than installing the harmonic damper
Last edited by MadAtComputer; 03-06-2024 at 12:22 PM.
Basically, the front face of the outer ring should be flush with the front face of the hub. The rubber insert that's between the hub and outer ring should protrude (or not) equally on the front and on the rear. You can't see the rear of the damper w/it installed but in that pic it looks like the outer ring has slipped and slid back some and the hub face appears to be "sticking out" further than the front of the outer ring. That will, at least, cause your timing marks to be off, making timing the engine more difficult than expected. At worst, the outer ring can slide back more and start slicing through your timing cover. When it slices all the way through, it'll leak a lot of oil.
It seems alright to me. When number one is at TDC the timing mark is right on. Spent a couple hours this afternoon cleaning up and painting the pulleys.
I have not given up, still working on it. Been going slow though. Partly due to hot weather, and we were getting my Dad's 96 trans am on the road.
Working on wiring and accessories before I can try and start it. figuring out the harness that the previous owner hacked up is not fun. And took a couple tries to get a throttle/TV cable bracket that fit. A jegs brand one worked out. Not a fan of the angle of the TV cable but it seems to move smoothly and adjust properly.
I picked up a OEM radio from a yard sale that supposedly is fully working for $5. Same as what my car has but a matte finish face plate instead of gloss. if anything I have a spare if I mess one up when repairing it. also got a hard cover chiltons shop manual for a couple bucks. that has been a nice help. Also got a non broken 84 front ground effect. Managed to find it on craigs list.
Tiny air cleaner is just there to keep things out of the carb when working on car.
Last edited by MadAtComputer; 08-10-2024 at 03:04 PM.
12-12-2023, 01:16 PM
I did not know about the nylon parts at all. I will replace them with modern ones. Current plan is to buy a melling m55 oil pump, the drive shaft for it that eliminates the nylon bushing, the correct pickup for the original 305 oil pan, one piece felpro pan gasket and a melling double roller timing chain.
