like it hits a wall

[ironcobra2002]

hi i have an 87 supra 7mge. sometimes when in 3rd and sometimes 4th about 4-5 thousand rpm it seams as if it starts to "gag" a little like it kinda hits a wall. it has aobut 187000 on it so i figure that its probably engine wear, rings worn out maybe causeing a little blowby and robbing me of compresion but i thought i might see if maybe someone might have some other insight that might be useful.