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Longhorn Man · 06-24-2002, 10:50 PM

Not sure if you've seen my post or not, but I am planning a 425 into my Longhorn. What are some of the things I need to know? I don't have too many details on the motor yet, as in what it came out of, what kind of oil pan, ect.
But what are the best motor mounts to use, what towers, will I have radiator inlet/outlet troubles...ect.
Stuff I have on hand include a TH350 hooked up to a Pontiac motor, 72 big block towers, '71 and older (much taller) big block towers, I can get small block ones if need be, even V-6 mounts if it'll make my life easier.
If you have or can get some pics of the details, that would help me 100%.
Can you help me?

Duallie · 06-25-2002, 02:33 AM

Get the rubber-insulated motor mounts with the engine. Beat (nicely!) the firewall rearward pretty much where the clutch linkage hole is. (The round plate on the firewall with two screws, located inboard of your throttle foot.) Set the engine in place without the oil pan but with the mounts installed. Bolt to your transmission. Hang the engine where it clears everything (including the exhaust) and weld in some channel from frame top down to the crossmember. The motor mounts will tell you where to put them. When the engine is supported, measure down from the oilpan rails to the crossmember minus an inch for clearance and cut everything off of the pan that won't clear. Plate over the gaping hole in the pan and weld on a new sump. Stretch the oilpump pickup with some 3/4" tubing (I used a new bicycle seat upright). Plumb and wire to suit.
The Cadillac upper radiator hose fits. I can get you the NAPA number for a lower hose that needs some customization. The heater hose out of the head could be a pain. I welded up a stailess 3/4" tube to snake from the back of the head around the valvecover (for easy removal) and back to the heater core. I had to fab the transmission linkage from stock parts. I didn't have room for a fan shroud. Don't use any thermostat but a Cadillac one. The oil filter cleared the front crossmember, but I relieved it anyway for hand room.

Thats how I did it.

mooneyes · 06-25-2002, 09:25 PM

if i remember correctly my buddy used a eldorado oil pan and didnt have to cut it and i know he used a remote oil filter..ill find out more and let you know..we also just picked up a cad motor for his longhorn yesterday

Longhorn Man · 06-25-2002, 09:39 PM

Sweet, keep the info coming!

PushinPebbles · 06-25-2002, 10:49 PM

I think in order to fit ..............you need a eldorado oil pan, main(for the oil pump),and the pump itself(I think , you might be able to use the old one)...................................jack

cadpowered · 06-26-2002, 11:00 AM

Longhornmail

Don’t know about the 425 but here is what we have done with the 500/472. The way I prefer, leaves the valve covers about an inch to inch and a half off of the firewall. You have to cut a small semicircle out of the front cross-member ( about 1 to 1 & 1/2 inches deep) to allow for the oil filter and take about 3/4 inch by about 5 inches off of the frame at the passenger side exhaust dump. You also need a rear sump oil pan El Dorado, I think that is it. If you do it that way your old automatic shift linkage will hook up and work (if use use the Caddy T400). The other way is to snug it up to about 1/4 inch off of the firewall, then you don’t have to do the front cross-member cut, not sure about the passenger side exhaust, I haven't done one this way yet. We use the Caddy motor-mount and fabricate/weld an adapter to the frame that the Caddy motor mount will fit.

Here are some post from the MTS forum (Maximum Torque) that might give you some ideas.

I used 1/8 flat stock bent at a 90 drilled too fit the block than welded that to the metal Chev mount that bolts to the block the end result is your able too use a stock Chev rubber mount that bolts to the frame. Hope thats clear,if not let me know.
----------------
I used stock mounts for a '70 Fleetwood 472 to install my Caddy in a Malibu.The mounts consist of two interlocking steel parts with rubber sandwiched between. The top part bolts to the block and the bottom has a stud and a locating dowel. I built two brackets on the crossmember with holes to accept the mounts. They are about an inch shorter than a Chevy setup will allow so they are useful in tight quarters.I bought the mounts at Carquest for $10.50 each.
-------------
There are 3 different oil pans available for the engine. Front, 3/4 rear and full rear sump pans. Determine the style your swap will need. Most GM midsize car swaps require an original 1968 - 1981 Eldorado or Seville oil pan. V-4-6-8 Cadillac engines in 1978 - 1981 Eldorado and Seville also work.
GM truck swaps can use the 425cid 3/4 rear sump pans. When you swap any oil pan to any other than the original engine it MUST have its pickup tube checked and adjusted. Clearance should be set to 3/8" to 1/4" from the pan floor
----------------
Be sure to change the ignition wire running to the distributor if you use the electronic ignition. The original wire is a resistance type, the distributor will not send the necessary 12 volts it needs. Trace the old wire to the point it exits the engine side of the fuse box. Cut the wire leaving about 1 inch and splice on your new wire. This is the case on all chevrolet trucks 1974 or earlier.

MOST IMPORTANT!! Go to Maximum Torque and read Al’s Cadillac Tech Info, FAQ’s, etc. you will find most of what you need is already there, also get on the forum for any detailed questions you might have. Hope this helps. Good Luck! Cadpowered

Longhorn Man · 06-26-2002, 04:48 PM

Been to the site...been printing up butt loads of info here.
Thanks.
Seems pretty cool that teh trucks can use the 425 pan.

Less $$ out of my pocket.
If anyone can think of anything more....let me know.

THOR 50 · 06-26-2002, 06:33 PM

if you don't have this link http://www.cad500parts.com/parts.htm

Longhorn Man · 06-26-2002, 08:04 PM

Kick @ss...I already had it, but ppl are trying.

thanks.

larouchedem · 11-25-2002, 07:12 PM

Duallie,

Good tip. Using a non-cad therm has caused many a hot running caddy. Using a non-cad therm allow coolant to short cycle instead of being pushed back through the block. Fyi - you can block the passage under the therm with a soft plug if you want to run a non-cad thermostat. Btw - the reason the hole is there is to allow for quick engine warm-up.
Dave

< Don't use any thermostat but a Cadillac one.

Longhorn Man · 11-26-2002, 12:53 AM

Wow...diggin up in the archives huh?
That's cool, I have been seeing those words for a while now, and never wanted to come out and ask why...thanks.

06-24-2002, 10:50 PM	#1
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	cadpowered.... Not sure if you've seen my post or not, but I am planning a 425 into my Longhorn. What are some of the things I need to know? I don't have too many details on the motor yet, as in what it came out of, what kind of oil pan, ect. But what are the best motor mounts to use, what towers, will I have radiator inlet/outlet troubles...ect. Stuff I have on hand include a TH350 hooked up to a Pontiac motor, 72 big block towers, '71 and older (much taller) big block towers, I can get small block ones if need be, even V-6 mounts if it'll make my life easier. If you have or can get some pics of the details, that would help me 100%. Can you help me?

06-25-2002, 02:33 AM	#2
Duallie Registered User Join Date: Feb 2001 Location: Nikiski, Alaska Posts: 477	Get the rubber-insulated motor mounts with the engine. Beat (nicely!) the firewall rearward pretty much where the clutch linkage hole is. (The round plate on the firewall with two screws, located inboard of your throttle foot.) Set the engine in place without the oil pan but with the mounts installed. Bolt to your transmission. Hang the engine where it clears everything (including the exhaust) and weld in some channel from frame top down to the crossmember. The motor mounts will tell you where to put them. When the engine is supported, measure down from the oilpan rails to the crossmember minus an inch for clearance and cut everything off of the pan that won't clear. Plate over the gaping hole in the pan and weld on a new sump. Stretch the oilpump pickup with some 3/4" tubing (I used a new bicycle seat upright). Plumb and wire to suit. The Cadillac upper radiator hose fits. I can get you the NAPA number for a lower hose that needs some customization. The heater hose out of the head could be a pain. I welded up a stailess 3/4" tube to snake from the back of the head around the valvecover (for easy removal) and back to the heater core. I had to fab the transmission linkage from stock parts. I didn't have room for a fan shroud. Don't use any thermostat but a Cadillac one. The oil filter cleared the front crossmember, but I relieved it anyway for hand room. Thats how I did it. __________________ Just as if I knew what I was doin'

06-25-2002, 09:25 PM	#3
mooneyes Registered User Join Date: Jan 2002 Location: Slippery Rock PA USA Posts: 1,692	if i remember correctly my buddy used a eldorado oil pan and didnt have to cut it and i know he used a remote oil filter..ill find out more and let you know..we also just picked up a cad motor for his longhorn yesterday __________________ Ken Lyons, Slippery rock pa 68 short step 327 t10 4 gear 72 2wd blazer project 70 lwb 305/700r driver 78 caprice project 02 cavalier D.D ( hate it!!)

06-25-2002, 10:49 PM	#5
PushinPebbles My dad's 68 Join Date: May 2002 Location: VA Posts: 444	I think in order to fit ..............you need a eldorado oil pan, main(for the oil pump),and the pump itself(I think , you might be able to use the old one)...................................jack __________________ Jack M. 67 C-10 SWB 355 built T-350 tranny hurst shifter 17x8in KMC's on michelins, clear tails and back up lights slammedUPDATE i have decided on my bag setup and will post further info when i recieve all the parts **************************** 88 1/2 ton suburban 4x4 350/700R-4having a 9 in lift w/ 38 in tires 4 12 inch Lightning Audios *************************** 87 silverado 3/4ton jacked up 10-12 inches black and rubberized bed coating 35 in michelans ************************** Dad's truck 68 C-10 stepside, 468 BB, tubbed, weld wheels, Nason black,lots more **************************** grand dads truck 68 C-10 stepside fuel inj. 350/700R-4soon in audi silver **************************** 84 toyota pickup 22R 5 speed 2WD slammed, shaved and all the body lines filled w/ buickGN scoop,bout to be sprayed in 2003 mustang green metallic w/ silver flames **************************** S/N=BIGGYTYME@aol.com (hydros) "No fat chics, truck will scrape"

06-26-2002, 11:00 AM	#6
cadpowered Registered User Join Date: Jan 2001 Location: Pueblo Colorado USA Posts: 38	cadpowered Longhornmail Don’t know about the 425 but here is what we have done with the 500/472. The way I prefer, leaves the valve covers about an inch to inch and a half off of the firewall. You have to cut a small semicircle out of the front cross-member ( about 1 to 1 & 1/2 inches deep) to allow for the oil filter and take about 3/4 inch by about 5 inches off of the frame at the passenger side exhaust dump. You also need a rear sump oil pan El Dorado, I think that is it. If you do it that way your old automatic shift linkage will hook up and work (if use use the Caddy T400). The other way is to snug it up to about 1/4 inch off of the firewall, then you don’t have to do the front cross-member cut, not sure about the passenger side exhaust, I haven't done one this way yet. We use the Caddy motor-mount and fabricate/weld an adapter to the frame that the Caddy motor mount will fit. Here are some post from the MTS forum (Maximum Torque) that might give you some ideas. I used 1/8 flat stock bent at a 90 drilled too fit the block than welded that to the metal Chev mount that bolts to the block the end result is your able too use a stock Chev rubber mount that bolts to the frame. Hope thats clear,if not let me know. ---------------- I used stock mounts for a '70 Fleetwood 472 to install my Caddy in a Malibu.The mounts consist of two interlocking steel parts with rubber sandwiched between. The top part bolts to the block and the bottom has a stud and a locating dowel. I built two brackets on the crossmember with holes to accept the mounts. They are about an inch shorter than a Chevy setup will allow so they are useful in tight quarters.I bought the mounts at Carquest for $10.50 each. ------------- There are 3 different oil pans available for the engine. Front, 3/4 rear and full rear sump pans. Determine the style your swap will need. Most GM midsize car swaps require an original 1968 - 1981 Eldorado or Seville oil pan. V-4-6-8 Cadillac engines in 1978 - 1981 Eldorado and Seville also work. GM truck swaps can use the 425cid 3/4 rear sump pans. When you swap any oil pan to any other than the original engine it MUST have its pickup tube checked and adjusted. Clearance should be set to 3/8" to 1/4" from the pan floor ---------------- Be sure to change the ignition wire running to the distributor if you use the electronic ignition. The original wire is a resistance type, the distributor will not send the necessary 12 volts it needs. Trace the old wire to the point it exits the engine side of the fuse box. Cut the wire leaving about 1 inch and splice on your new wire. This is the case on all chevrolet trucks 1974 or earlier. MOST IMPORTANT!! Go to Maximum Torque and read Al’s Cadillac Tech Info, FAQ’s, etc. you will find most of what you need is already there, also get on the forum for any detailed questions you might have. Hope this helps. Good Luck! Cadpowered

06-25-2002, 09:39 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Sweet, keep the info coming!

06-26-2002, 04:48 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Been to the site...been printing up butt loads of info here. Thanks. Seems pretty cool that teh trucks can use the 425 pan. Less $$ out of my pocket. If anyone can think of anything more....let me know.

06-26-2002, 06:33 PM	#8
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	just in case if you don't have this link http://www.cad500parts.com/parts.htm __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

06-26-2002, 08:04 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Kick @ss...I already had it, but ppl are trying. thanks.

11-25-2002, 07:12 PM	#10
larouchedem Registered User Join Date: Nov 2002 Posts: 36	cadpowered Duallie, Good tip. Using a non-cad therm has caused many a hot running caddy. Using a non-cad therm allow coolant to short cycle instead of being pushed back through the block. Fyi - you can block the passage under the therm with a soft plug if you want to run a non-cad thermostat. Btw - the reason the hole is there is to allow for quick engine warm-up. Dave < Don't use any thermostat but a Cadillac one.

11-26-2002, 12:53 AM	#11
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Wow...diggin up in the archives huh? That's cool, I have been seeing those words for a while now, and never wanted to come out and ask why...thanks.



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