Orbitorange

I have searched and read, and read and read through alot of posts here and the information is overwhelming.Alot of the information is old that I find and alot of the new information contradicts alot of the old info since the swaps have become more popular. I just have a few questions that Im hoping to get a straight answer on. Before I start my conversion. I will also list what parts I plan to use.

1970 GTO
2004 5.3 with 4l60E
F body oil pan
F body intake manifold
F body accessories
F body factory exhaust manifolds

I understand the F body alternator will require the possibility that I might have to grind on the steering box. Im ok with that.

I had planned to use the S&P style 1 inch setback conversion plates as I understand it will let the F body oil pan clear the crossmember with out notching the crossmember. But that it might cause the passenger side valve cover to contact evaporator box. I really do not need contact with the evap box. My car is fully restored and the firewall is painted the body color and I rather not have to remove that evap box or modify it. So my question is. What mounts can I use that will over come both the evap box issue and the F body oil pan issue or is that even possible. Really dont want to go very tall on the mounts because that posses the issue of trans tunnel modification also.

2nd, alot of posts say the F body stock exhaust manifolds will work with the A body conversion. But yet some posts say they will not work. Which is it yes or no?

Im sure I will have more questions very soon. Right now I am cleaning all the accessories and putting new gaskets into the engine so that I have a fresh clean engine bay afterwards like I do now. Then the next step will be to mock it all up in the engine bay. Once that is done I will move on to fuel system and then onto the wiring and pcm mods.

oldgoat69

Having done a similar swap, I can advise the use of truck style brackets. It all fits with only a PS pulley swap. Based upon others experience you will need to notch the crossmember. If you use a dedicated swap pan everything will simply fall into place. It seems that F manifolds will work with little to no modification. I did not have to modify the tunnel, only the trans crossmember. I can supply a list of swap components if you are interested.

garys 68

iTrader: (1)

The F body pan is VERY tight. Consider the CTS-V pan with standard plates. Those plates will move the engine/trans mounting face forward about 1 1/4" and give you clearance for the AC.
Btw, I put a 5.3 in my 72 442, love it.

Orbitorange

Would love to see more pics of your swap and parts list.

Orbitorange

Where is the best place to get this oil pan ? As far as price is concerned.

garys 68

iTrader: (1)

Check out this thread.
You'll need the pan, pickup tube, O ring, maybe windage tray and dipstick/tube too.
https://ls1tech.com/forums/conversio...body-swap.html

Orbitorange

Ok so what adapter plates for the block and which mounts to use with the ctv-s pan? I prefer not to use BMP or whatever.

Ok I just read Gary suggest 1 inch set back plates.

Orbitorange

Just read that and 8 pages of your build. Good stuff.

garys 68

iTrader: (1)

I used the 1" setbacks since I was running a Muncie and got rid of the big AC box. I think you can run the standard plates and still clear the crossmember with the cts-v pan. Dirty Dingo makes adjustable plates if you need something in between. The oher possibility is to get the chevelle frame mounts and redrill the crossmember for the best fit.
Pretty much everyone has been putting a 1/4" spacer between the block and motor mounts for a better fit.
Also, lots of issues with the inner tie rod ends contacting the pan. I would suggest removing the inner tie rod grease fitting, plug the hoels, drill and tap for a new fitting pointing down.
Btw, a few more A body conversions:
https://ls1tech.com/forums/conversio...2-gm-body.html

oldgoat69

Frame mounts #3379 www.carpartsdiscount.com
Headers Dougs, best fit out there.
Engine adapters Dougs SK100
Motor mounts Energy Suspension 3-1117G
If you are using truck accessory mounts you will most likely need to change PS pulley to Dorman 300-123.

Don't waste time with the truck pan, it wont work out well. I used Canton 13-274 with pickup 13-275 and filter mount 22-631. There are a host of others as well that won't require cutting the k-member.
I can supply pictures if you are interested.
Plenty of room around the AC box even with the headers.

I used all of the truck accessory brackets and ac compressor. You will need to do a bit of surgery on the ac bracket to clear the motor mounts, nothing that a sawzall cant take care of.

I used a Northern Radiator LS conversion part and made brackets to mount late F body fans.
Brendon at www.lt1swap.com reflashed the PCM to make it all work. I still need to have some dyno time to sort out the trans shift patterns.

Good luck and have fun, feel free to contact me for more info any time.

Orbitorange

Oldgoat69. I cant get those frame mounts to pull up on that site.

You spent $500+ for the oil pan set up or something like that. Im gonna have to try the ctvs or modify my f body pan

oldgoat69

I think I spent more like $300.00 for the pan and oil filter adapter. Look at the Holley or Mast pan. If these were available at the time I would have used one of them. The frame mount stands are just sbc in 68-72 Chevelle. They bolt right to the crossmember with no modification. You can get the engine to sit higher, but I needed all the hood clearance I could get.

garys 68

iTrader: (1)

Lots of places still sell the chevelle mounts. Try the parts place, year one, opg.
I found mine used on ebay.
Here's what you're looking for.
http://www.ebay.com/itm/Chevelle-El-...b675c0&vxp=mtr

Houston_t

iTrader: (2)

Everyone says its a tight fit but I used a f body oil pan and 1" setback adapters from ebay on my 71 cutlass mostly because I already had it from my trans am I was about to do a swap in. Also heard I would have to use the f body exhaust manifolds but again since I had the truck ones on hand I figured I would give it all a try before buying new parts and it all fits fine to me. ( that's a thread I started in the above listed post )

Orbitorange

So the 1 inch setbacks with f body pan fits, its just very tight. Ok what transmission and driveshaft are you running?

Orbitorange

I dont mind if I need to remove my transmission to get the engine out. I have a lift in my garage and a transmission jack, so removing transmission is like an hour job. I just want to use my stock drive shaft when all is said and done.

Houston_t

iTrader: (2)

im not installing my transmission till the engine is in its final resting place, after that see no need to pull it back out so having to remove the trans to get it back out doesnt bother me either. i wanted to go with a overdrive trans but i have a 350 so i may just put that back in so i dont have to worry about messing with the driveshaft and crossmember

chuckd71

iTrader: (23)

I used the dirty dingo mounts and I like them well enough. And I think the grease fittings are already in the flat part of the tie rod ends on 70s, I used all 70 stuff to replace my 71 steering components for just that reason.

Orbitorange

Racking my brain to death with all this conversion info. I feel like I am in overload right now.

Old goat, so you used a 4l60e transmission. Thats what Im going to use (I hope thats what this thing is). Did you have to modify the trans tunnel to fit it in there? Were you able to reuse your stock drive shaft or did you have to have it modified? I was just out in the garage measureing. Looks like the poncho 350 is 22 inches long and the TH400 is 28 (from what I found online with a 4 inch tailshaft) For a total of 50 inches long. And my 5.3 block is 20 inches long and the transmission is 31 for a total of 51 inches. So front of block to tail of transmission I am going to be loosing 1 inch of drive shaft length? If I am correct that means hopefully I have enough length in the trans for 1 more inch of the slip yoke. Or else I gotta do 1 of 2 things. Move engine 1 inch forward, or have drive shaft shortened by 1 inch.
I know I am beating this subject to death but with so many options out there for motor mounts, adapter plates. Im trying to get as close as possible to what I have in there now with the Pontiac 350 and TH400 trans. so I dont have to buy a new drive shaft. And Im facing the problem with the f body oil pan (unless i get a killer deal on a ctvs pan). So with what I said previously. Im loosing 1 inch, then if I retain f body oil pan I have to set back an additional inch for clearance there! So that puts me at cutting 2 inches off the drive shaft length!

What should I do guys or am I overthinking this to much? I just want to buy the right stuff the first time. I dont want to be buying multiple oil pans, drive shafts, and engine mount plates!

1981TA

iTrader: (7)

I would go with truck or corvette accessories. I did the later and didn't have to notch or grind anything.

When I originally put my engine in, all I did was bolt it to the stock TH350, which was in turn bolted in the stock position on the trans mount, line the engine up on the frame and tack weld in the lower mounts. You have an A-body, and things may be slightly different, but the general process may work for you. Doing the mockup costs nothing but time, and you'll be able to more accurately make your measurements.