Hey guys, new member here. My son is currently in the process of buying a 65 GTO, down payment has been made, should have the GOAT home in another week or so.

He wants to put a set of headers and a nice exhaust system on it and also larger wheels/tires (currently has bias ply redlines and 14" Ralle I's). What's the largest size tire that he can go with on the 65 with 15" Ralle I's on a 7" wheel in front and an 8" wheel in the back? Also I have been reading some posts on Doug's headers. Any feedback on installation ease/problems for the 65 (no power steering or brakes) with a 4spd (might convert over in the spring to a 350/400 turbo because of a medical condition)? Thanks for the tips/advice, look forward to being an active member of this board.

Hey guys, new member here. My son is currently in the process of buying a 65 GTO, down payment has been made, should have the GOAT home in another week or so.

He wants to put a set of headers and a nice exhaust system on it and also larger wheels/tires (currently has bias ply redlines and 14" Ralle I's). What's the largest size tire that he can go with on the 65 with 15" Ralle I's on a 7" wheel in front and an 8" wheel in the back? Also I have been reading some posts on Doug's headers. Any feedback on installation ease/problems for the 65 (no power steering or brakes) with a 4spd (might convert over in the spring to a 350/400 turbo because of a medical condition)? Thanks for the tips/advice, look forward to being an active member of this board.

Hi- I can't give you much help regarding your questions, but I wanted to welcome you, so....Welcome!

Dick

welcome,

be forewarned, headers suck on the 65's. at least they do on mine.

if you aren't going to race it on a regular basis i think i'd go for a set of the ho manifolds instead.

not sure on the wheel / tire ?'s, check out the suspension forum for more info on tire sizes and the fit of them. there're multiple threads on this issue and you should find one that answers your ?. if not start a new thread.

i'm going to copy this to the lobby also.

mike

I have Doug's headers on my 64 Tempest and they fit great. The passenger side is a bit of work to get into the chassis, but once it is in you can get a box wrench on every header bolt. This is an automatic, so check with Doug for the 4 speed fit. You can get a good deal on the headers at Pacific Performance Racing (Ken "Ace" Brewer) at 310-832-4596.

http://www.jimspontiac.homestead.com/Index.html

http://kurtsplates.homestead.com/files/jimplate.jpg

Welcome .....

I have a 65 and went with the HO cast iron manifolds and then fitted 2.5" pipes all the way back. I got mine from Torque Tech, but the exhaust kits they sell here at PY look great also.

good luck with you car. and don't be afraind to ask even the simplest questions.

...best if used on or before date indicated...
65 GTO

Welcome from another newcomer,

As far as the tires I have a set of P225/75R14's on Cragar SS's and they are very tight on my 65.

hey poncho mike, welcome to the py forum. I have a 65 with the 15x7 rally repros and I can run BFG radial TA's. Front 215/70-15, Rear 255/60-15. This will keep your tire diameter around 27.1 -27-3 inches which is similar to what GTO's had originally but with the added benefit of wide radials. If you want to have the same size all around you may be able to squeeze 225/70-15 in front and back but this changes the diameter and the front may rub, which is never good. My cars previous owner had 245/60-15 all around and the front fenders got warped from the tires rubbing.
Hope that helps, email me if you want more info, [email protected].
Mike

Welcome. Have to agree with some of the others regarding the headers. Dougs are great, but only if you are going to race. HO manifolds are the way to go for increased performance and durability. Costs less and less hassle.