ffmpeg – convert pcm audio to ac3 without changing the frame rate?

I have PCM audio which has frame rate of 199.964 FPS (240 SPF). When I convert it to AC3 the frame rate changes to 31.250 FPS (1536 SPF). This causes sync issues and I dont want to convert the video again. So is it possible to change the audio frame rate separately.

Command used to convert to AC3

`ffmpeg -i out.wav -c:a ac3 -b:a 448k out.ac3`

Original audio info

Format : PCM
Format settings : Little / Signed
Codec ID : A_PCM/INT/LIT
Duration : 2 h 18 min
Bit rate mode : Constant
Bit rate : 1 536 kb/s
Channel(s) : 2 channels
Sampling rate : 48.0 kHz
Frame rate : 199.964 FPS (240 SPF)
Bit depth : 16 bits

Converted audio info

Format : AC-3
Format/Info : Audio Coding 3
Commercial name : Dolby Digital
Duration : 2 h 18 min
Bit rate mode : Constant
Bit rate : 448 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 31.250 FPS (1536 SPF)