![]() |
Register or Log In To remove these advertisements. |
|
|
![]() |
|
Thread Tools | Display Modes |
![]() |
#1 |
Registered User
Join Date: Jul 2007
Location: Wisconsin
Posts: 8
|
Engine Swap - 1971 4WD - Small block to Big block
HELP HELP - I have a 1971 GMC 4WD I would like to install a 502CID Big Block Chevrolet in. Does anyone have or know of a kit that includes the engine mounts that are affixed to the frame rails that includes a cross member as well?
I am concerned about where to bolt up engine towers in relation to the distance from the fire wall and also how it will effect all other placement of drivetrain components. I have the 502CID and also a beefed up 700R4 and NP205 transfer case. At this juncture I am contemplating the purchase of a small block engine mount and cross member kit from DIY4X4. Since it is the only kit I've found I was thinking I might modify the cross member to try and make it work for a big block. Spacing is still an unknown from the firewall however. I realize this will most likely effect the positioning of the transmission cross member as well, which leads me to ask, is there a cross member kit available for it also?? I look forward to you help. If you should prefer to call, my cell phone is 414-378-9234 or my email is mksmith@trinitypetroleum.com Last edited by Mark Smith; 08-20-2007 at 05:51 PM. Reason: Mistake |
![]() |
![]() |
![]() |
#2 |
Post Whore
![]() Join Date: Feb 2000
Location: Rose Hill, KS, USA
Posts: 12,689
|
Re: Engine Swap - 1971 4WD - Small block to Big block
I haven't dealt with any of the automatic transmissions so I don't know how long your 700R4 is compared to an TH350 or TH400. Assuming it is longer I would sure think moving the motor forward would be the way to go. Someone who has moved their motor forward will chime in on how much forward you would need to move it to be sure to have no firewall issues.
Would really enjoy seeing some pics of this project. Blown 502 ci just peaks my interest big time!!!
__________________
1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14 |
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Jul 2007
Location: Wisconsin
Posts: 8
|
Re: Engine Swap - 1971 4WD - Small block to Big block
It will be a while before pictures to my standard and worthy of on-lookers are available.
For now, all of the body and interior work has been completed. The truck is canary yellow with a gray tweed interior and oak floor in the bed with stainless trim. I am pleased with the body and interior progress. I have rewired all of the truck with the Painless wiring kit. The cab is set up for air conditioning also. The engine compartment is canary yellow as well. The truck has a 6" suspension lift. I did not go nuts on lift because I want more of a proportionate look over all. I have a canary yellow blown gas 1969 Camaro as well. I plan to pull the drag car on a gloss black open car trailer with the blown gas 1971 4WD Pick up. The combination should be a nice eye catcher. Thanks for your support. |
![]() |
![]() |
![]() |
#4 |
Senior Member
![]() Join Date: Apr 2000
Location: madison indiana
Posts: 3,839
|
Re: Engine Swap - 1971 4WD - Small block to Big block
sounds awsome.. it don`t have to be done to share pics!! lol
__________________
jamie72 72 BB cheyenne -- Restoration getting started.. member #807 http://www.myspace.com/whitetailobsession www.antlertalk.com |
![]() |
![]() |
![]() |
#5 |
Registered User
Join Date: Dec 2006
Location: Trinidad, Colorado
Posts: 642
|
Re: Engine Swap - 1971 4WD - Small block to Big block
I used cross-member and motor mounts out of an '80 3/4 ton. I have about 3 inches clearance from my dist to the firewall, and about 1 inch on the valve covers. I did have to open the hole forward a bit for my sm465 though. From what I've read on this site....I would just bolt it in the stock location and beat the firewall where necessary. This will save you all the other mods, including drivelines!!! It sounds like you could do it in a way that looks good....artistic hammer work!!!
![]() ![]()
__________________
69' 3/4 4X4 470ci BBC 700 HP.... ![]() D60/14bolt 205/465 http://profile.myspace.com/index.cfm...ndid=127691959 |
![]() |
![]() |
![]() |
#6 |
Post Whore
![]() Join Date: Feb 2000
Location: Rose Hill, KS, USA
Posts: 12,689
|
Re: Engine Swap - 1971 4WD - Small block to Big block
That will be a sight to see when you get the truck done and hook it to that trailer.
I have to agree with jamie72 - we love seeing progress pics around here. The finished product is nice to see but I really enjoy seeing the work people put into their trucks. What kind of times do you get out of your blown Camaro?
__________________
1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14 |
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Jul 2007
Location: Wisconsin
Posts: 8
|
Re: Engine Swap - 1971 4WD - Small block to Big block
Hello again,
The blown Camaro is not all that fast. I see consistant 1/4 mile et's in the 10.10 to 10.20 range. With a little suspension work I think it would see 9's but I never wanted to narrow and tub the car. So, all things considered I put up with 10's and don't plan on doing anything more to the car for now. I used to run top alcohol IHRA in the dragster category with a 280" Hal Canode chassis. Aries 8 Liter Hemi with 1471 supercharger. That car was 6 seconds in the 1/4 so modifying a Camaro to hilt doesn't particularly interest me all that much. Any how, we'll see about getting the gang a few photos one of these days. In the mean time, I certainly appreciate your input. Thanks, Mark |
![]() |
![]() |
![]() |
#8 |
Senior Member
Join Date: Dec 2003
Location: Kingsport TN
Posts: 4,641
|
Re: Engine Swap - 1971 4WD - Small block to Big block
you could use this one it is from ORD and made for a big block $189 . I hope your going to spend some cash on that 700 a 502 will eat that trans up.
http://www.offroaddesign.com/catalog...rossmember.htm
__________________
Earl 68 2500 4x4 GMC Burb |
![]() |
![]() |
![]() |
#9 |
Senior Member
Join Date: Dec 2003
Location: Kingsport TN
Posts: 4,641
|
Re: Engine Swap - 1971 4WD - Small block to Big block
For got speed way is an option as well and they are the cheapest but theres are all universal so some cutting and welding required.
__________________
Earl 68 2500 4x4 GMC Burb |
![]() |
![]() |
![]() |
#10 |
ROCKWELL 5 TON CLUB !!
![]() Join Date: Oct 2006
Location: indiana
Posts: 516
|
Re: Engine Swap - 1971 4WD - Small block to Big block
the diy4x engine crossmember set is nice...
super strong and very nice work,using one to put ls1 in 1970 k5.only custom mounting to get 1" forward and 3" down.
__________________
1970 K5 "ON THE ROCKS" PROJECT:500hp 6.0 fuel injected. 2wd sm465 trans,t136 2.5 ton transfercase,5ton rockwells with 9.34 gears,custom wheel disc brakes,full hydro steering20+" OF LIFT AND 67/35/25's..67" tall TRACTOR TIRES.."THE MUD SLUT!!" MY BUILD THREAD: http://67-72chevytrucks.com/vboard/s...d.php?t=221935 1997 TAHOE,SAS D60 14B,5:13 DISC BRAKES,CROSSOVER STEER,HYDRO ASSIST,42 IROKS HINT:NEW NAME "K5ontheROCKS!" |
![]() |
![]() |
![]() |
#11 |
Registered User
Join Date: Jul 2007
Location: Wisconsin
Posts: 8
|
Re: Engine Swap - 1971 4WD - Small block to Big block
Yes thanks, I am aware of this cross member but it is really designed for the 73 and newer stuff. My truck is a 1971. I'm actually thinking of using both this for a cross member and frame stiffiner in conjunction with the DIY 4X4 small block kit. We'll see, I'm still getting feed back from everyone. Not sure who you mean my Speed Way. Thanks again
|
![]() |
![]() |
![]() |
#12 |
Registered User
Join Date: Jul 2007
Location: Wisconsin
Posts: 8
|
Re: Engine Swap - 1971 4WD - Small block to Big block
I'm assuming you mean 1" from the fire wall right? What are you referring to when you say 3" down?
|
![]() |
![]() |
![]() |
#13 |
Senior Member
Join Date: Dec 2003
Location: Kingsport TN
Posts: 4,641
|
Re: Engine Swap - 1971 4WD - Small block to Big block
Speed way is a race parts place kinda like jegs but with a lot more custom parts and parts with there name so you can get a better deal . There mainly known for hot rod parts if you dont have a catalog from them I would get one there great for off the wall stuff . here is a link to there universal cross meber
http://www.speedwaymotors.com/p/3273...0MOTOR%20MOUNT
__________________
Earl 68 2500 4x4 GMC Burb |
![]() |
![]() |
![]() |
#14 |
ROCKWELL 5 TON CLUB !!
![]() Join Date: Oct 2006
Location: indiana
Posts: 516
|
Re: Engine Swap - 1971 4WD - Small block to Big block
the diy kit is for 1st gens:
http://www.diy4x.com/engine.htm it is very nice... yes i mean 1" forward....gave me a little extra firewall room,plus an extra 1" on rear driveshaft length. by 3" down, i mean i made a 3" channel to box in the frame at the engine crossmember.which lets the engine crossmember still bolt in,just 3" lower. that will help keep center of gravity lower and help with frt and rear driveline angles((my k5 will have aprox 20" of lift!))
__________________
1970 K5 "ON THE ROCKS" PROJECT:500hp 6.0 fuel injected. 2wd sm465 trans,t136 2.5 ton transfercase,5ton rockwells with 9.34 gears,custom wheel disc brakes,full hydro steering20+" OF LIFT AND 67/35/25's..67" tall TRACTOR TIRES.."THE MUD SLUT!!" MY BUILD THREAD: http://67-72chevytrucks.com/vboard/s...d.php?t=221935 1997 TAHOE,SAS D60 14B,5:13 DISC BRAKES,CROSSOVER STEER,HYDRO ASSIST,42 IROKS HINT:NEW NAME "K5ontheROCKS!" |
![]() |
![]() |
![]() |
#15 | |
Registered User
Join Date: Jun 2007
Location: Phx, Az
Posts: 51
|
Re: Engine Swap - 1971 4WD - Small block to Big block
Quote:
|
|
![]() |
![]() |
![]() |
#16 |
Registered User
Join Date: Oct 2003
Location: Central Vermont
Posts: 8,537
|
Re: Engine Swap - 1971 4WD - Small block to Big block
|
![]() |
![]() |
![]() |
#17 |
Registered User
Join Date: Jul 2007
Location: Minnesota
Posts: 22
|
Re: Engine Swap - 1971 4WD - Small block to Big block
My guess is that if you have painted your engine compartment you are not going to want to do any firewall bashing. I am getting ready to start a similar build next week. Its a 1970 K10 swb fleet. I am using a 454/TH400/NP205. I will be moving the entire setup forward to allow a plenty of room so I dont have to use a prybar to change the distributor cap. I am a fabricator by trade so I will be fabricating my own mounts and crossmember. I will be doing it all with the body off of the frame with a lot of reference measurements so it should be a piece of cake. Good Luck
|
![]() |
![]() |
![]() |
#18 |
Registered User
Join Date: Jan 2007
Location: Bellingham, washington
Posts: 260
|
Re: Engine Swap - 1971 4WD - Small block to Big block
Put a big block in my 68 and used all the 68 parts. Just moved all crossmembers forward 1 and a half inches. I did have to use stock valve covers and put a small quarter inch by two inch long notch in the frame for the driver side headers (hookers). There were a few things moved for my 4 speed but your not using that. I even used the small block motor mounts.
__________________
68 4x4, 454, 4 speed, disk brakes both ends, Sold my 69 SS396 Elcamino when young & stupid ![]() |
![]() |
![]() |
![]() |
#19 |
Registered User
Join Date: Sep 2006
Location: Portland
Posts: 135
|
Re: Engine Swap - 1971 4WD - Small block to Big block
I'm putting in an LS2 into a 72 4x4 and I just got the diy4x4 crossmember and some S&P engine mount relocators. When I went to bolt everything together I found that the mounts on the LS engine are about an inch farther apart than an old style small block. Did you run into the same problem?
I can fab up some new motor mounts but I was a little dissappointed that the engine mount relocators didn't put the engine mounts in a factory position. BTW, I tried out the diy4x4 crossmember on a big block I had around and it did not clear the oil pan. However it was not a stock oil pan. |
![]() |
![]() |
![]() |
#20 |
Registered User
Join Date: Dec 2006
Location: Trinidad, Colorado
Posts: 642
|
Re: Engine Swap - 1971 4WD - Small block to Big block
I'm gonna do this again here shortly......My question is if I ran tall valve covers, with engine in stock location, how much firewall will need to be removed? And, is there anything back there I should be worried about moving first before I go to cutting?
Thanks, A..........
__________________
69' 3/4 4X4 470ci BBC 700 HP.... ![]() D60/14bolt 205/465 http://profile.myspace.com/index.cfm...ndid=127691959 |
![]() |
![]() |
![]() |
#21 | |
Registered User
Join Date: Sep 2006
Location: Portland
Posts: 135
|
Re: Engine Swap - 1971 4WD - Small block to Big block
I had tall valve moon style valve covers on my 454 and no issues with the firewall. I did not do the swap so I'm not sure where the stock location is but the engine stands were in the forward holes. There was about 1/4 inch clearance from the back corners of the valve covers.
Quote:
|
|
![]() |
![]() |
![]() |
#22 |
Currently Blazerless
Join Date: Apr 2000
Location: St. Joseph Mo.
Posts: 4,828
|
Re: Engine Swap - 1971 4WD - Small block to Big block
While the DIY4X4 crossmember is a quallity peice, I dont believe it will work in your case. I'm using one and oil pan clearance is very tight with my stock small block oil pan.
__________________
1972 C/30 133" W.B. C&C 1970 GMC 3500 157" W.B. single wheel C&C |
![]() |
![]() |
![]() |
#23 |
Member #1049
Join Date: Jun 2000
Location: Troy Montana
Posts: 3,940
|
Re: Engine Swap - 1971 4WD - Small block to Big block
If your truck came with a T350/205 combo from the factory switching to a big block and using a 700R4 is one of the easiest ways to go!
The 700R4 is just over 2 inches longer than a T350. Leave the trans crossmember and transfer case in the stock location which means no mods to drive lines, shifter etc, doing so puts the big block far enough forward for valve cover to firewall clearance. Then you could use just move the stock small block engine cradle forward to fit and drill 8 holes, but if you are concerned with strength then maybe opt for the 73 and up 4X4 front crossmember that uses the "clam shell" style mounts which are known to be stronger than the 71's, If I remember correctly you will have to mod the crossmember a bit and will have to drill all the holes in your frame to mount it. Good luck with your swap.. PICTURES PLEASE!!! |
![]() |
![]() |
![]() |
#24 | |
Recovering 67-72 Addict
![]() Join Date: Oct 2000
Location: North Bend, WA
Posts: 1,788
|
Re: Engine Swap - 1971 4WD - Small block to Big block
Quote:
__________________
68 Short Fleet 4x4; 427; BTO Level 3 700R4; NP205; Dana 60 front and rear; 4" lift with 35's; Disc brakes; AGR variable ratio steering; factory bucket seats; factory tach and tilt. "Friends call me cruzer cuz I like fast cars and fast women" |
|
![]() |
![]() |
![]() |
#25 |
Registered User
Join Date: Mar 2007
Location: oklahoma
Posts: 118
|
Re: Engine Swap - 1971 4WD - Small block to Big block
i spoke to the guy at diy4x today and he said that his cross member should work with a big block. He did say that stock oil pans should clear better than aftermarket because they are more rounded in front so i looked at mine and i believe he is right i should know more soon.
|
![]() |
![]() |
![]() |
Bookmarks |
|
|