![]() |
Register or Log In To remove these advertisements. |
|
|
![]() |
|
Thread Tools | Display Modes |
![]() |
#1 |
Registered User
Join Date: Feb 2019
Location: Colts Neck, NJ
Posts: 14
|
L6 to V8 weight bias significance
Hello! I've swapping a 250 out for a 383, and I've been doing a lot of reading about the process for a long while.
I was planning on placing the engine in the original V8 spot because I don't want it to feel cramped, but from what I've read putting it in the L6 spot might give better weight bias and improved handling. My question is: is this noticeable, and enough so that it's worth putting the engine further back? Or is it just a good reason to not move it if you're hoping to avoid the work. Thank you for your time as always! |
![]() |
![]() |
![]() |
#2 |
Who Changed This?
![]() Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,395
|
Re: L6 to V8 weight bias significance
Moving the V-8 forward might not be that advantageous, given that GM did it differently. What do you plan to do with your truck that makes that bias an advantage?
__________________
~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA |
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
Posts: 916
|
Re: L6 to V8 weight bias significance
Unless you’re planning on using the truck for weekend road course duty or drag racing I would consider the positioning completely insignificant. I would simply go with whichever position makes the swap the easiest and most cost-effective.
Steve weim55 Colorado |
![]() |
![]() |
![]() |
#4 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,859
|
Re: L6 to V8 weight bias significance
The simple answer is "No". People didn't simply relocate the mounts forward where they need to be mostly because they didn't know any better. Didn't even know the engine was sitting back too far. All they knew is it dropped right in. Most didn't know the mounts were different either
Personally, I think it's silly to be concerned with such non-significant weight bias on a TRUCK. These aren't sports cars. Trucks are built to add weight to. AND, do people think the engineers at GM didn't know what they were doing? Why question what they did? PLUS... the reason the I6 mounts are farther back (just a couple inches) is because they are longer. So the weight is spread about the same, only a bit lighter with the six. Not that the truck will feel it. If you want a noticeable improvement in weight bias, move the engine to right behind the cab ![]()
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 02-05-2020 at 07:13 AM. |
![]() |
![]() |
![]() |
#5 |
Registered User
Join Date: Feb 2019
Location: Colts Neck, NJ
Posts: 14
|
Re: L6 to V8 weight bias significance
Awesome - thank you for the responses! I'm going to move the mounts forward then to the original location. Now to try to find a v8 manual trans cross-member
![]() |
![]() |
![]() |
![]() |
#6 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,717
|
Re: L6 to V8 weight bias significance
I'd leave it the 6 cylinder spot. Save the money. Easier to bend the exhaust to rams horns manifolds, no need to relocate transmission, use same driveshaft. etc.
__________________
44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
![]() |
![]() |
![]() |
#7 |
Senior Member
![]() Join Date: Dec 2013
Location: Gods country East,Tn
Posts: 8,545
|
Re: L6 to V8 weight bias significance
It's your truck so you decide which way to go . But when I did mine I had to switch everything to the V8 position and found the V8 manual trans cross member off the parts board from another member . I had to change mine because it would have driven me crazy (crazier) every time I opened the hood and saw the V8 sitting in the rear holes with it's distributor up against the firewall knowing that it's not the way V8 trucks came from Chevy . Yes it cost more and involves more work and parts but Gm did it that way and that's a good enough reason for me.In the pictures you can see the V8 cross member is heavier and how it sits further forward in the frame
![]()
__________________
![]() 1967 Factory short bed - Old school '71 - 350 / 4bolt / 487 heads / Edelbrock C3BX Muncie M-22 4 speed / Hurst Comp plus Factory 12 bolt posi 3.73 / 255-70-15 Smoothed firewall / Factory cowl induction Power disc brakes / power steering / 3.5-5" drop |
![]() |
![]() |
![]() |
#8 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,717
|
Re: L6 to V8 weight bias significance
If you own a 67-72 Chevy truck V8 and 4 wheel drive, the engine sits right up against the firewall just like it does when you mount it in the 6 cylinder position of a 2 wheel drive truck. So in that sense, yes, they were mounted that way form the factory.
I wouldn’t discount the effect of moving the motor back a little on performance would have either. Moving the battery from front to rear on a muscle car can have a noticeable effect on balance and traction. Moving 800# back 4” does make a noticeable difference depending on what you goals are. 4” less driveshaft can make a difference as well if you are running a 1 piece. Like everything else, it depends on what your goals are what might be best for you. I am inherently cheap, and I don’t know what your plans are for transmission but I would change and spend as little as possible to do a GOOD, CLEAN, PROFESSIONAL looking installation.
__________________
44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
![]() |
![]() |
![]() |
#9 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,859
|
Re: L6 to V8 weight bias significance
I've driven these trucks with V8s in both positions and they all drive the same to me. But I don't do slalom. Figure GM used the same springs for small block and six. I'm keeping the apples with apples and oranges with oranges in my comparisons. I never noticed any difference in handling with dual batteries or aluminum heads either. Or driving alone vs with a passenger. The key word here is significant and that's what is generating my replies. That's why my simple answer is no. I understand the economics stand point and, honestly, either position is fine for me.
As far as oranges go, most of my experience has been with 4wds and the motor tucked back just that little bit makes it a PIA when it comes to the distributor. When I helped a friend put a 700r4 in his '67 Panel on a '72 Suburban K/10 chassis, the economical and way less labor way to go was the opposite. Move the engine forward. All pluses. Engine out of firewall, only move engine mounting, no transfer case crossmember moving, no floor mods (transfer case lever hole), and no altering two driveshafts. But you never hear of people moving there engine forward in a 4wd to get it out of the firewall. Most likely because it's even more work and expense... AND, it's just no big deal either way.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
![]() |
![]() |
![]() |
Bookmarks |
Tags |
250, 383, engine swap |
|
|