[1966gmachine]

Well it’s been a while and finally back on the Chevelle. Got Holley 1” forward mounts Holley 302-3 pan and its fighting me at every angle. I’m close right now with using 1/2 spacers in between the motor and the motor mounts but I’m not happy and it feels like the trans is hitting all over the place? Anyone run into this issue or have any recommendations?

 

[1966gmachine]

This is how my pan is fitting with Holley 302-3 pan and forward position mounts. I even have a 1/2” spacer to see if that would do the trick.

 

[Jasons 69 Chevelle]

4l60/65 will not fit without modifications to the tunnel.

 

[fauxrs]

I Ran with a 302-2 pan in my '67 which should be all but identical to your 66. The 302-3 is similar but not quite the same dimensionally and I know if I ran the 302-3 in my 67 with the 1" forward bias blackheart mounts it wouldn't have fit, it would hit the crossmember where it transitions to the sump.

this is the 302-1 and 302-2 comparison

this is the 302-3 according to my google-fu - this pan is deeper where it transitions to the sump and the slope is steeper which would lead me to believe that's where its hitting.
That Chevelle runs a 4L60. I don't know if the L60 is dimensionally the same as the L65 but the tunnel had to be massaged with a mallet to clear the cooler lines. If it were raised up in the tunnel due to a high engine, it wouldn't stand a chance of fitting.

This is how snug my pan is to the crossmember - it doesn't touch anywhere despite the appearance.

 

[Bronze68]

4l60/65 will not fit without modifications to the tunnel.

Ditch that thing and get a 4L80. Vastly stronger, and a smaller case. No tunnel work if the bell housing mounting plane is the same or very close to original.

 

[69_CHEV_ELLE]

^ This was true for my 69. Is the 66 tunnel the same? IDK.

 

[Alwhite00]

I'm using 1" setback mounts with the -2 pan and it fits great. I'm running a 4L60 and its tight in the tunnel on my 67. I'm guessing you are going to have to open the tunnel a bit for that trans.

 

[Alwhite00]

 

[RatchetRay]

Ditch that thing and get a 4L80. Vastly stronger, and a smaller case. No tunnel work if the bell housing mounting plane is the same or very close to original.

4L80 is absolutey stronger, but it's also bigger. If OP is having fitment issues with the 4L65, the 4L80 definitely won't fit. 4L65, 4L60, and 700R4 are all the same case size.

 

[1966gmachine]

Thanks for the help guys, I’m going to call Holley today and probably order the 1” setback mounts.

those using the setback mounts how’s the clearance at the firewall by the intake?

 

[Alwhite00]

Thanks for the help guys, I’m going to call Holley today and probably order the 1” setback mounts.

those using the setback mounts how’s the clearance at the firewall by the intake?

This is my firewall clearance. Keep in mind I did this before the Holley kit was available and is just generic 1" setback mounts. If I were to do it now I would buy the complete Holley kit.

1

 

[Bronze68]

4L80 is absolutely stronger, but it's also bigger. If OP is having fitment issues with the 4L65, the 4L80 definitely won't fit. 4L65, 4L60, and 700R4 are all the same case size.

Sorry - I was typing too fast there. True as noted, 4L60 is absolutely smaller - what I meant to get across is that their cases are shaped such that they will not fit an A-body tunnel without some modification/massaging, and without modification, the driveshaft angle will be way too much. A 4L80 will without a doubt fit in. Might need the banjo fittings for the cooler lines depending upon an early or late case, but still no tunnel change.

Caveat: if keeping the 50-year-old body bushings - it may hit. A good set of new bushings, rubber or polyurethane, and there's plenty of room.

 

[B52bombardier1]

The Holley forward-bias engine mounts can solve a lot of these problems. And did, with the 4L60E in my 70 EC - no tunnel cutting required. And a good angle towards the differential.

Rick

 

[Jasons 69 Chevelle]

The 4l80 is smaller in size in the narrow part of the tunnel. It does weigh more though. Mind blow right.

 

[1966gmachine]

I’m using new poly body bushings and the forward bias mounts did some massaging of the tunnel already. Im going to try the reward mounts and see if I can get it in. My concern now is if my intake manifold will hit the fire wall as it sits now I have maybe 1.5 inches of clearance.

 

[B52bombardier1]

It would have been tough with my LS swap if I had kept the original AC evaporator case on the firewall. The intake manifold might not have fit using my LS truck tall manifold.

Rick

Sent from my SM-G965U using Tapatalk

 

[LSA Chevelle]

Use the GM clamshell mounts that the system was designed by Holley to work with