Portugal could even in our timeline turned Red. The Portuguese revolution was very leftist, and after the fall of fascism socialism was even put in the constitution. However, by the late 70's right-wing winds were blowing, and socialist reforms were cancelled, the collective farmers driven of the latifundias etc. However, had the communist party acted decisively with support of some of the existing left-wing groups of officers, they kight have taken power in a coup. In a more Soviet Europe, the likelyhood of that increases.
As for Spain.... Well, if the fascists refuses to reform themselves away as they did OTL, when democracy was essentially given to the people by the king, I could see Spain going down in flames. And in such times radicals relish.
I know that for outside observers

, it sometimes looks like the Carnation Revolution in Portugal was very leftist oriented, but the Revolution was made by many people on the right too (the original
National Salvation Junta was overwhelming conservative, and the mid-levels of the
Movement of the Armed Forces had a strong presence of the centre-left and centre-right).
The far left was very vocally visible, but that didn't mean popular support.
They just turned very visible because some more right wing sectors of the revolution were scared by the far-left and attempted a show of civilian force (the
Silent Majority episode of
30 September 1974, to pressure more radical leftist elements of the
Movement of the Armed Forces to back down the from the left-wing course the movement was taking: the demonstration by civilian supporters of conservative provisional President General
António Spínola was blocked by the Communist Party and its occasional far-left allies) and later tried a coup (the
11 March 1975 attempted coup, a more desperate attempt from more conservative elements close to Spínola to turn the course of things), getting weakened in the process at the eyes of part of the military.
Nevertheless, the majority of population and the military (like
Spínola's sucessor, General
Francisco da Costa Gomes, a left wing independent democratic socialist) was firmly committed to Democracy (even though the far-left was overrepresented in the
Council of the Revolution, successor of the aforementioned
National Salvation Junta, and effectively the upper echelon of the
Movement of the Armed Forces). The electoral results in the 1975 and 1976 elections gave very clear and solid majorities to democratic parties (the Socialists, Popular-Democratics and Centrists).
A Communist revolution requires a social and economic environment (landless city or rural workers with no tradition of personal property) that didn't exist in most of the country (only most of Alentejo of the time, and part of the Lisbon residents of the time, fitted that description).
In the case of Spain, the same socio-economic conditions would not favor a communist regime.
It's necessary a much earlier POD that alters the economic and social structure of both countries.