EJ engines seem to have very little torque on idle in my experience eg need 1200/1500rpm to pull away in 1st gear on the flat without slipping the clutch to avoid stalling on EJ 251 SOHC on my (2nd Gen Outback) and the EJ 251 SOHC is noted to have better mid range torque values than DOHC ( SOHC has a flatter torque curve) (most of torque happening by 3000rpm - pulling stongly @ 2500rpm even though max torque quoted at 4000rpm)
The head design / valve configuration is different between DOHC / SOHC engines. DOHC engine better for top end than SOHC, SOHC better mid range than DOHC, even though actual power/torque quoted for both is not that much of a difference .
EJ engine max torque values range from 2800 to 4500rpm.
Probably the best EJ engine to use is the notorious (internal head gasket failure) earlier versions of EJ25D coz max torque @ 2800rpm
EA82 SOHC (1800) which I have had 2 of was similar to EJ251 pulling away too (max torque @ 3200rpm) in which EJ engines were based on.
Probably the best engine to use is the EA 81 (ohv 1800) ex Brat / 2nd gen Leone
l have one (87 Brat) and its much stronger on idle (torque) than all the previous I've mentioned ie (max torque at 2500rpm)