TR4/4A tr4 front suspension question

[TR4v8]

I have one of the early tr4 chassis & am curious if its feasible to swap in the later tr4-tr6 control arms & trunnions to get the better arms/balljoints & the built in caster from the later trunnions? I've found a tr6 parts car that I can rob the front assembly out of, but need to know if this is a bolt in type swap or a total nightmare. if doable, would it be worth it or are the gains minimal? thanks!

 

[TR4nut]

Its doable I think. A very good reference is available from Tony Drews: https://www.tonydrews.com/Front_Suspension/tr4_front_suspension_upgrade.htm

The one slightly questionable area are the tie rod levers- I think the TR6 ones will be too long, you would probably need to stick with your TR4 ones. That might lead to some bump steer issues potentially but I don't know that for a fact. Options in that case would be levers for a later 4 or 4A which both had the 3 degree castor trunnions so the geometry might be a little better.

Not sure about gains, but I'm contemplating a similar change in the TR3A I'm building - the 0 degree castor setup is fine on the car I drive, but the self centering of a 3 degree setup I like a little better. If you have a V8 in that 4 or yours, the TR66 vertical links are beefier which can't hurt things. Look at Tony's site, you'll see the difference.

 

[TR4v8]

thanks for the link! that info is exactly what I was looking for.