1967-72 Is the first time they changed the frames entirely between 2WD to 4WD. You have to use an aftermarket engine crossmember for 4WD frames to fit an LS or an LT GEN V. in 1968 when BBC's became an available option and they started to make the top of the frame rails skinnier to fit the exhaust. 2WD V8 frame perches require a specific motor mount with the through-bolt going vertical unlike most SBC Gen 1 motor mounts. Stock V8 Frame Perches use the front holes on the frame.
The skinny crossmember piece directly below the firewall in this photo is a bellhousing brace for manual transmissions. This is not an integral frame support and will have to be removed to use a rear mounted transmission crossmember. You may not even have the bolt holes in the frame for a transmission crossmember if your vehicle came with a manual transmission, you will have to make your own mounting bolt holes.
You can see on the left here that straight six engines used an additional bracket on top of the stock V8 frame perch/motor mount setup.
1968-1971 BBC Frame Perches had a larger hole for the through bolt and required a rubber puck from the underside. Cheap workaround is using a large washer in place of the puck or closing the hole up with some welds. You can get replacement BBC 68-71 rubber motor mounts from LMC with part number 34-0329. You need to order two.
68-71 BBC Frame Perch and Motor Mounts with underside Puck
New small block frame perches click here.
1972 BBC frame perches actually have the clamshell style just like 73-87(91) Square Bodies. In the following photo, A is the "Clamshell" with a rubber isolator and "B" is the metal motor mount bracket that bolts to a SBC/BBC GEN 1. "B" is most commonly reffered to as the "Elephant Ears" and is no longer available from GM and there were many different types throughout the years. OER and other companies make reproduction brackets but you have to understand that they are not a one size fits all. 2WD and 4WD 1973-1991 C10 "B"s will not interchange for instance. Clamshells started to phase out the old Short and Wide/Tall and Narrow style in 1972.
Unless you have the Elephant Ears that went from the clamshell to the BBC, you would need to run our 73-87 C10 LS Conversion mounts.
72 BBC Frame Perch and Stock 3 Bolt Clamshell
The passenger side Frame Perch's hump tends to get in the way of exhaust. You can cut off the hump that rests on the frame rail and make it flat for better fitment. These here were also gusseted underneath for additional strength.
These are stock 2010-2015 Camaro exhaust manifolds
OER makes reproduction frame perches for SBC and BBC. Typically people go for the SBC perches as they have the small through bolt hole and don't require the additional rubber puck from underneath like BBC requires. They do not currently reproduce the 1972 BBC frame perches. 1960-62 will need a one-inch spacer block on top of the frame rail where the frame perch will rest on for correct geometry. If doing the Square Body V8 frame perch conversion, the C20's fit better than C10's.
*Pre-notched for DD-Slider's/DD-LT-Glider's
63-72 V8 C10 SBC Energy Suspension Mount is 3.1156G (Poly)
LS GEN III/IV and LT GEN V Conversion Mount Options for 2WD Frames:
LS Motor Mount Conversions:
(Starting out in raw non painted steel so make sure you paint them before the final install otherwise they will rust. Otherwise they are offered in black textured powdercoat for a small additional charge)
*Not compatible with low mount AC and passenger side motor mount requires a notch on the lower side
LT Motor Mount Conversions:
*Not compatible with low mount AC and passenger side motor mount requires a notch on the lower side
Transmission Crossmember:
New transmission crossmember version (not shown) has an adjustable center piece so you can perfect the driveline angle you need
LS GEN III/IV and LT GEN V Conversion for 4WD Frames requires an aftermarket engine crossmember
1967-72 4X4 LS Conversion Cross Member
Crossmember designed to use 4-bolt Clamshells and the adjustable conversion mounts that are in the drop-down menu in the item listing. Using the drop down menu's on the item listing discounts the clam shells and adjustable conversion mounts required. When selecting the powdercoat option for the 4X4 engine crossmember, we include free powdercoat for your adjustable conversion mounts as well. Can be used with Big Block or Small Block engines when using factory steel outer block side clam shell from 74-87 4X4 trucks. Gen III/IV engines will require using a Holley 302-1 oil pan and Gen V engines will require using a Holley 302-20 oil pan.
454 BBC with 73-87 4WD Elephant Ears
"Using the front brake line hole as as guide moved engine forward about an inch which worked out well for about 1-1/2" distributor clearance at top of cap from firewall. Short valve covers will be needed with a little bit of clearancing at the corners. Very pleased with the product. Good job. Thanks"
Useful Links:
http://www.persh.org/pickup/IdeaPage.htm
Exhaust
Schoenfeld Long Tube 1 3/4" with 5/16 flanges, 16ga primaries, 02 Seconor bungs installed in collector, and excellent spark plug access. Temporary non-high temperature paint.
Fits 2WD frames.
Schoenfeld Long Tube 1 3/4" with 5/16 flanges, 16ga primaries, 02 Seconor bungs installed in collector, and excellent spark plug access. Ceramic Coated.
Fits 2WD frames.
Hooker block hugger manifolds. Fits 2WD and 4WD frames.
Speed Engineering Shorty Swap Headers
25-101
Power Steering
A stock gearbox will have inverted flare. It is a common for one to swap to an 1980+ gearbox.
|
|
Pressure |
Return |
|
LS Power Steering Pump |
M16x1.5 O-Ring |
Hose Clamp |
|
Before 1980 Gearbox (SAE) |
5/8"-18 |
11/16"-18 |
|
After 1980 Gearbox (Metric O-Ring) |
M16x1.5 O-Ring |
M18x1.5 O-Ring |
If your O-ring is old and hard, use the following part number for replacements: GM 26001594.
DO NOT use any O-ring you find at the parts store. The Metric O-Ring fitting requires an O-Ring made of Viton so the power steering fluid doesn't destroy them.
O-Ring Technical Info: 903 (7.65mm ID x 1.63mm C/S or .301 ID x .064 C/S) Viton
If your vehicle has the Metric O-Ring fittings, then your power steering lines will bolt straight up to any power steering pump offered in an LS application. Make sure there isn't an O-ring already in the power steering pump from the old line!
If your vehicle has the SAE fittings AND the 3/8" lines line up to the back of your LS power steering pump, all you need is THIS ADAPTER to be threaded into the high pressure port on the pump. The power steering pump side is M16x1.5 with a Viton O-Ring while the power steering line will fit a 5/8"-18 Inverted Flare.
3/8" Line threaded into the adapter fitting on the back of an LS truck power steering P pump
Check out
Lee Power Steering for all your GM gearbox needs. They can rebuild and do precise valve tuning to give you that exact steering you are looking for!
Engine Accessories
There is a lot of room in C10s and most accessory brackets fit other than stock LS compressors (without notching the frame). Dirty Dingo low mount ac for LS GEN III/IV clears the frame, it may require moving the engine slightly more forward than stock position. Truck spacing would move the bracket to the furtherst forward mounting hole and allow you to push the engine back further than Camaro or Corvette spacing would allow you to go.
1960-1972 C10 Engine Acessory Example
Jason Bowman from Big 10's '69 C10
Additional helpful links:
Restoration Tips
Auto Metal Direct Catalog
Everything body relates from hoods, grilles, windows, truck beds, all the way to the rubber grommets in the firewall.
