Charlie Posted January 31, 2008 Share Posted January 31, 2008 I just got a Vortec 4.3L out of a 1998 truck through my work, and i was able to find the motor mounts and the T-case adapter through AC, has anyone done this swap before? Any problems or snags that I should address before I start? I plan to do this over a weekend at our shop, and it has to be out of the bay by monday, so I would like to be able to crank most of it out in that time. I have the engine, tranny, and all associated harnesses and a computer. I figured I will have to make drivelines, and maybe a tranny and t-case crossmember, but other than that, can any of you see any obvious problems? I am doing the swap, because it is more economical for me than rebuilding the VG30 and auto tranny (270,000 and starting to get some piston-slap) Link to comment Share on other sites More sharing options...
packie88 Posted January 31, 2008 Share Posted January 31, 2008 i dont think anyone on this board has done a 4.3L swap, better off sticking to the AC boards and asking them Link to comment Share on other sites More sharing options...
Charlie Posted January 31, 2008 Author Share Posted January 31, 2008 (edited) Ok, well, I haven't spent any money yet, as the motor was free because it came out of a totaled company truck, How easy is it to swap the later VG30E into the 87? They go for about 400-500 for a 30k-50k motor around here. Is it a matter of bolting it to the stock transmission and obtaining a new computer, do I need the VG30e trans to go with it? I could get the whole bundle for about 800 through work probably. what about the VG30DE? Edited January 31, 2008 by Charlie Link to comment Share on other sites More sharing options...
packie88 Posted January 31, 2008 Share Posted January 31, 2008 you could shove the VG30e in there no problem, not so sure about the de, would require alot of work. the pathies dont have much engine compartment room. what engine does your 87 currently have. tranny should be a direct bolt up. Link to comment Share on other sites More sharing options...
sw Posted January 31, 2008 Share Posted January 31, 2008 theres at least two of us on here that have done it using the australian spec of the engine if the yank version is anything like the aus version forget the vg, the gm motor absolutely flogs it. as for getting it done in one weekend, that a little ambitious to say the least you may have motor mounts and an adapter, but its going to be far from bolt in. what trans are you using & what mount are you going to use to hold it. there will be masses of stuff you havent planned on i.e how are you planning to wire it up? what fuel pump setup are you planning on?, you will need to fit a surge tank, how are you doing your air intake? etc etc etc a big heads up now is what radiator are you planning on using? i tell you now these bigger motors get hot in our little engine bay. i was regularly seeing 95-98 degrees celcius coolant temp - although never ever had a problem & it would go all day like that. if i were to change it now i would go a completely custom completely aluminium 1 or 2 row cross flow job. to give some perspective i took six months of most of my spare time to complete my conversion. vsicks is the other on here to do the swap & he was in a similar situation. to get it done right you cant rush it all that being said - GO FOR IT you wont look back Link to comment Share on other sites More sharing options...
BowTied Posted February 2, 2008 Share Posted February 2, 2008 I have not done the swap, but I have a 99 Jimmy 4.3L 4x4. This is a great engine. What I would like to mention: The engine uses a fairly high pressure fuel system, higher than many according to one mechanic I talked to (~50psi range?). Make sure your fuel pump is up to it. The Jimmy fuel pump is a pricey little bugger too. You might want an afermarket pump. Some 4.3s have intake gaskets leaks, check this out before putting it in. a 98 4.3L likley used Dexcool coolant (reddish colour). DO NOT mix the old green stuff in with it unless the container says it is compatible. It will ruin the engine. I would recommend a coolant system flush after you get it together. The 4.3 is a 90 deg V6, it is wide. As noted routing wires etc could be fun. I would look to a dual electric fan set-up. The 4.3s have the centre spark plug located right behind the steering column from the factory, unscrupulous garages will "forget" to change that plug. Most garages just bend the heck outa the shaft for clearance. check your plugs to be sure they are easy enough to get out (not seized) before the swap. A lot of folks say not use Bosch plugs in a 4.3L. I recommend the OE delco plugs, can't go wrong there. They are a little pricey though. If you are using the OE wiring and computer, you will need 3 O2 sensors in the exhaust - likely easiest to use the Y pipe that came with the engine if it will fit. Hope that helps. I would agree that this would be hard to do in one weekend even if you had done it before. If you do tackle this project (I hope you do!!!) Please take pictures and post your progress. Link to comment Share on other sites More sharing options...
jj big shoe Posted February 2, 2008 Share Posted February 2, 2008 Since you'll be doing so much work anyway, ever though about dropping in a SBC? http://www.aggressiveoffroad.com/Pathfinder.htm http://www.aggressiveoffroad.com/pthpndr8.htm http://www.aggressiveoffroad.com/v8Path.htm http://www.aggressiveoffroad.com/PathfinderSAS4.htm Link to comment Share on other sites More sharing options...
Charlie Posted February 3, 2008 Author Share Posted February 3, 2008 I have an aluminum Howe radiator in the truck now, that i stole from my project car cause the pathy one gave up the ghost. I have the entire 1998 Chevy 1/2 ton truck complete with wiring harness, computer, fuel system etc. as for the condition of the motor, it was rebuilt about 30,000 miles ago, along with the tranny, and was my shops parts runner for a long time, It has been regularly maintained and well taken care of, I would have no issues with questioning the condition of the motor. As stated, I work in a shop, have all the tools and equipment necessary I seriously think I could pull it off with two full days in the shop. As for the air intake, I will probably just run a cone filter over the OE inlet tube. Link to comment Share on other sites More sharing options...
88pathoffroad Posted February 3, 2008 Share Posted February 3, 2008 I have not done the swap, but I have a 99 Jimmy 4.3L 4x4. This is a great engine. What I would like to mention: The engine uses a fairly high pressure fuel system, higher than many according to one mechanic I talked to (~50psi range?). Make sure your fuel pump is up to it. The Jimmy fuel pump is a pricey little bugger too. You might want an afermarket pump. Stock fuel pressure for a VG30E is 43 or 46, I forget. The Nissan pump will push up to 70 unregulated PSI IIRC, the pressure regulator is the bottleneck. Get a different FPR and you'd probably be in business. Link to comment Share on other sites More sharing options...
tmoore4512 Posted February 26, 2012 Share Posted February 26, 2012 I know this is an old thread, but what 88 stated about the FPR bottle neck is absolutely true... Believe it or not, mine failed... (or rather was in the process of it) and stuck wide open.... had 68 PSI at the injectors... OUCH!!!! Link to comment Share on other sites More sharing options...
Slartibartfast Posted February 27, 2012 Share Posted February 27, 2012 ... I have to ask. What happens when you have 68 PSI at the injectors? Link to comment Share on other sites More sharing options...
tmoore4512 Posted February 27, 2012 Share Posted February 27, 2012 To reiterate, I checked the fuel pressure via the procedure outlined in the FSM, and I can only assume that it was in fact putting the 68 PSI to the injectors... I had to replace 2 of them, and I assume that down the road I will have to do the other 4... The two I replaced were stuck open and no matter how much tinkering I did they would not break free. Link to comment Share on other sites More sharing options...
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