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73-87 Chevy _ GMC Trucks => Performance => Topic started by: higgins81 on April 09, 2009, 12:55:40 am

Title: Engine upgrade on 85 C10 w/4.3L
Post by: higgins81 on April 09, 2009, 12:55:40 am
I just bought a 85 C10 w/4.3L V6 and is thinking of putting a V8 in it.  How much harder would it be to put in 1999-00 4.8L or 5.3L instead of a rebuilt 350?
Title: Re: Engine upgrade on 85 C10 w/4.3L
Post by: KoolerSL2 on April 09, 2009, 01:21:45 am
first welcome to the site.
ive done the 4.3 to V8 swap lil over a year ago.
best to find a donor truck that was a v8 to get the frame sections that the motor mounts bolt to.
the 4.3 sections set back too far and have different motor mounts.
do a search and a few threads will show up with more swap info.

as for the newer LS-series based engines theres a few members on here who have done it so do a search on that also.

chris
Title: Re: Engine upgrade on 85 C10 w/4.3L
Post by: Captkaos on April 09, 2009, 08:40:26 am
It is not complete but view this post, it is a work in progress of my LS conversion.  I wouldn't think twice of doing a LS conversion.
http://forum.73-87chevytrucks.com/smforum/index.php?topic=5225.0
Title: Re: Engine upgrade on 85 C10 w/4.3L
Post by: eventhorizon66 on April 09, 2009, 10:37:44 am
Before I decided on my current engine, I had to decide whether I wanted a hot rod motor or a stockish cruiser.  When I decided on the latter, I definitely should have gone down to the local auto dismantler and picked up a low-mileage 5.3/4L60E drivetrain.  I still kick myself for not doing that.  I was intimidated by the wiring and the hidden costs mainly.  But there is just too much useful info available to anyone performing this swap for that to be a legitimate excuse.  There are a few guys here running LS-engines that could help you out.  Also check out http://www.ls1truck.com/forums/lsx-truck-conversions/.
Title: Re: Engine upgrade on 85 C10 w/4.3L
Post by: Stewart G Griffin on April 09, 2009, 07:46:31 pm
And with cylinder deactivation on the LS engines, you could be looking at 20+ mpg.   But i still won't do it because i'm choosing to say no to electronics----for now.
Title: Re: Engine upgrade on 85 C10 w/4.3L
Post by: choptop on April 09, 2009, 09:20:26 pm
My work truck have the cylinder deactivation thing on it. Its an 08 Chevy 1/2 ton z71. My previous truck was an 04 z71 with the 5.3. I have not seen any better mileage with the 08 and I think the 04 would kick its behind in a race. I bought it because the other one had almost 150,000 miles ( tho it never had a problem) but when you are self employed, warranty on a vehicle is a good thing and its a write off as well.
Title: Re: Engine upgrade on 85 C10 w/4.3L
Post by: zieg85 on April 09, 2009, 09:33:19 pm
Welcome to the site from NW Indiana.