The Bucc required one pylon just to carry the targetting pod for the Martel. A problem with internal stowage is that you are often limited to the weapons it was designed to carry. Another problem with the engine mod is that the tailpipe drags along the ground. Titanium castors.
Clearly an aircraft that should have been built...
https://www.alternatehistory.com/discussion/showthread.php?t=198573
Here's a mini TL for it:
USSR see a potencial export market for a dedicated antiship aircraft in the late 60s. Tu16K too big and expensive, Su24 too far away and expected to end up as too sophisticated anyway, soo, Yak comes up with inexpensive solution.
The Yak28K was built as a mix of the Yak28PM and Yak28I. A new radar was fitted and to get good performance the jet was reengined with the R25 engine from the MiG21bis. Since all exiting soviet AShM missiles were regarded as too large, a new missile based on the ARM Kh28 was developed. The Aircraft was built in a number of small series tailored for export costumers:
Yak28MKC - Exported to Cuba (24 aircraft/1973). Optimised for high speed low altitude attack in a high threat environment. Single missile carried internaly, an option that was regarded as very useful by Cuban pilots since the USN tends to be very agitated when "Red" aircraft with visible AShM fly close to its warships...
Yak28MKI -36 aircraft Exported to Iraq in 1984. Extensively used in the tanker war with Iran. Modified to carry two missiles externaly, in an instalation similar to Yak28PP. 12 flown to Iran in 1991, later modified to carry chinese built AShM
Yak28MKS - 12 Exported to Syria in 1986. Similar to cuban aircraft.
Yak28MKV - 36 aircraft exported to VietNam in 1988. Final variant built, improved missiles and radar.