Author Topic: ls7 swap  (Read 6452 times)

Offline 78blackbeauty

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ls7 swap
« on: July 07, 2010, 02:43:55 PM »
i wanna swap in an ls7 into my truck. i have a 78 gmc heavy half. shes blue right now but later on she will get a nice flat black paint job. the ls7 is a 427 out of the vette. idk how to do the swap all the way but its going to happen. info on this would help greatly. also idk how to post pics on here so help please
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Offline Captkaos

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Re: ls7 swap
« Reply #1 on: July 08, 2010, 02:19:56 PM »
LS7 is just a stout LS block, alot of people are swapping them in.  So any LS thread here will help you.  YOu can look in the tech section and the sticky at the top tells you how to post pics.

Offline 78blackbeauty

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Re: ls7 swap
« Reply #2 on: July 09, 2010, 11:22:41 AM »
cool thanks
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Offline Gandalf1969

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Re: ls7 swap
« Reply #3 on: July 09, 2010, 11:44:47 AM »
Plan, plan, plan.  It's tedious I know and I don't want to rain on your parade - it's an exciting project for sure.  But take the time to sit down and write a list of EVERYTHING else you will need to make this happen and be honest with yourself.  The swap from Gen1 to LSx has some considerations with $ attached.  Not impossible, just make sure you know what they are and how much you will be in by the time you are done.  You can safely figure 50%+ of the engine cost depending on how much you do yourself.  THEN add the "LS7 tax" - that's a beast by itself as not everything transfers over from other LSx platforms.  So even if you think your engine came "complete', consider what you will do for wiring, dry-sump (or even the cost of conversion to wet sump), fuel system, exhaust (incl O2), tuning, sump pan compatibility, radiator (different), a/c if you have that, accessories (mounting and wiring), trans compatibility (your existing won't work without modification and neither will the vette trans, sensors just to name a few.

That's all I can think of off the top of my head but from experience - figure even if you got a deal on the engine and "everything" from the vette, you may be up for the same cost again to get it in there and running.  Less if it's not LS7 because there's simply more parts and information out there.  So depending how much work you do yourself and what you have already, figure a super conservative $3k-$5k to get it in and running.

Talk with and listen to people who have ACTUALLY COMPLETED the conversion you are doing.  Mine is in a 69 Camaro so there are plenty of differences but the same principles apply.  Do your homework and there will be no surprises.

LS1tech.com is a great reference site for the engine side of things.  Good people there even though it's not a truck-focused site.


G.
« Last Edit: July 09, 2010, 11:47:29 AM by Gandalf1969 »

Offline team39763

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Re: ls7 swap
« Reply #4 on: July 12, 2010, 11:11:35 PM »
Are you dead set on the LS7?  There's similar LS motors that can compete with the LS7 for less money and less hassle.  I had planned on doing the LS7 swap, but I think I can make that much or more power with less hassle by sticking with the more common motors....Like a LS3 stroked to either 418 or 427 with either a set of ported LS3 or LS7 heads. 
« Last Edit: July 12, 2010, 11:13:59 PM by team39763 »

Offline 78blackbeauty

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Re: ls7 swap
« Reply #5 on: July 12, 2010, 11:16:19 PM »
the reason i chose the ls7 is for the mpg and the hp. its 505 horses and about 20 to 30 mpg and its going into my daily driver. if you have any suggestions that will fit these guidelines, all is welcome
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Offline Captkaos

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Re: ls7 swap
« Reply #6 on: July 12, 2010, 11:22:20 PM »
Normally Aspirated, Boosted, Carb'd or EFI.
You can take a 6.0L LQ4 drop a cam in it and make almost 500hp at the crank.

Offline 78blackbeauty

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Re: ls7 swap
« Reply #7 on: July 12, 2010, 11:25:02 PM »
efi and good mpg
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Offline team39763

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Re: ls7 swap
« Reply #8 on: July 13, 2010, 01:04:37 PM »
I believe there's a guy on Tech that has a LS3 stroked to 418 with ported L92 heads and he's getting good gas mileage.  If I remember correctly he puts down 550+HP to the wheels.  I'll get more info on his combo and his contact info...he's a really cool/helpful guy.  LS7 just seems like an expensive hassle with all the not-so-common parts.

Offline 78blackbeauty

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Re: ls7 swap
« Reply #9 on: July 13, 2010, 03:46:07 PM »
cool thanks. i want power but its for a daily driver so mpg is a big part. right now i get about 15 to 16 mpg but its not enough because i only work part time
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Offline team39763

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Re: ls7 swap
« Reply #10 on: July 14, 2010, 12:06:46 PM »
The guy goes by WKMCD on LS1tech.  I think he just changed his setup though.  His old combo was a LS3 stroked to 416 with WCCH L92 heads and a small custom cam.

Offline Captkaos

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Re: ls7 swap
« Reply #11 on: July 14, 2010, 01:23:11 PM »
Budget?  What is your current trans/gearing?

6.0L is the cheapest route to get to where you want to be.

Offline TexasRed

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Re: ls7 swap
« Reply #12 on: July 14, 2010, 01:32:30 PM »
You don't have money for gas but you have money for a fairly intense swap?  ???

Offline Captkaos

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Re: ls7 swap
« Reply #13 on: July 14, 2010, 01:44:27 PM »
yeah, read cheap as it is going to cost $2000 for and engine/trans combo with ECM, $400 for someone to go through the wiring extra junk ($600 for aftermarket plug/play), $400 new fuel lines, hoses, pump and sending unit.  $100 for mounting, $500 for headers, or manifolds with Exhaust, $400 for new exhaust, $400 for radiator.......

And when you are done you are probably going from 15mpg in the city to about 18 or 20....  The most I have seen out of a 73-87 with an LS (and the driver wanting to see the best mileage) is 25mpg driving 80% HIGHWAY and not more than 55mph..  Yeah 55mph.

Offline 78 Chevyrado

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Re: ls7 swap
« Reply #14 on: July 14, 2010, 06:35:20 PM »
yeah, read cheap as it is going to cost $2000 for and engine/trans combo with ECM, $400 for someone to go through the wiring extra junk ($600 for aftermarket plug/play), $400 new fuel lines, hoses, pump and sending unit.  $100 for mounting, $500 for headers, or manifolds with Exhaust, $400 for new exhaust, $400 for radiator.......

And when you are done you are probably going from 15mpg in the city to about 18 or 20....  The most I have seen out of a 73-87 with an LS (and the driver wanting to see the best mileage) is 25mpg driving 80% HIGHWAY and not more than 55mph..  Yeah 55mph.


I can't drive, 55!  ;D
Kenny

1978 C-20, 350/400, 3.73, Graystone Metallic, Raceline Renegade 8 Wheels - 18x8.5, 275/70R18 BFG KO's