need info on 1971 motorand frame mounts?

[james69z28]

I SENT THIS TO 1 MEMBER, but wanted to get it to lots more:
i am building a show truck, 1971 that i bought half finished and i put the march serpentine setup on the front of my 383 small block and then when trying to install a custom big aluminum radiator in it i found that i need about 3/4" clearance between my a/c compressor pulley (coned) cover and one of my electric cooling fans. so I want to be sure the frame mounts are bolted in the correct holes for a small block, I saw your pic you posted of your motor mount but I can't see enough to tell, are the frame mounts on your engine using the forward mounting holes or the rear that are about 2" further back?
I can remove my frame mounts and drill the motor mount bolt hole about 1/2" rearward and may be able to get a little more clearance on the core support , I cut the side rails near the opening and I gained about 1/4" of clearance. I just had a driveshaft made to accomadate the motor and 700r4 trans, if I had not just bought this I have enough room to go back 2 inches everywhere so I could use the rear mounting holes but I don't want to pay to shorten the drive shaft and it appears that the HEI distributor may not be able to be removed if I go that far back?
could you verify that your frame mounts are bolted in the forward or rearward holes for me? Thanks, I searched thousands of images on the net but can't seem to find anything that I feel confident in?
Thanks in advance for any help or pics!

[james69z28]

anyone?
I am about to drill my own set of holes halfway between the 2 factory sets, to avoid shortening the driveshaft?

[Grumpy old man]

Change the radiator ,Not the drive line .

[kwmech]

For a cleaner install you can use the big block frame stands and it will move the engine back 1-1/4'' using the front bolt holes.

[Steeveedee]

If you do move the engine back, just know that you will need to look at how much "extra" space you have on the spline on the driveshaft, and that you will probably have to cut an equivalent amount out of the exhaust system, depending on how close your mufflers are to the frame, back by the rear axle.

As far as changing the radiator, how is he going to make it thinner and keep it cool?

[james69z28]

All good info, esp. On the big block mounts, i thought that might be the case. I redrilled 3 holes in the frame on both sides and bolted the frame mounts 1 1/4" further back., i did remove the driveshaft i had built 2 weeks ago and had it shortened 1 1/2". Been waiting on headers 2 months now-so no exhaust involved!

Now the only problem is i am looking for some custom billet upper radiator mounts to hold the entropy radiator tighter to the core support, i removed the original lower mounts and installed 2 new ones, mounted to the widest position, for a 4 core radiator but when i tried to use the upper new ones for a 4 core it holds the radiator out over 1 " away from the core support --towards the engine. I do not know why because it sits tight to the core support on the bottom? So if i need to get someone to build some, i will. i have seen some nice polished billet ones, just dont know who makes them?