Originally Posted by: Devo 
Hi all.
Quick question.
What if any mods are worth doing to an early pre pollution 308 if you intend on retaining the following.
Stock air cleaner.
Stock carby but may be performance built.
Stock inlet manifold but could have some internal mods.
Stock heads but some valve work is fine.
Stock bottom end.
Stock headers.
Factory style dual exhaust but could be a little bigger.
Electronic ignition.
May go a slightly bigger stall in the 2 speed if that helps
I'm going for a fresh rebuild but I want it to look factory in the engine bay.
I'm not after big HP obviousely. I'm just interested that with all the stock bits I'm retaining. Is it even worth putting a better cam in or head work.
With the headers and inlet manifold choke everything down anyway.
Great to hear everyone's thoughts.
Cheers
Stock air cleaner, look for a higher air filter maybe to give it 10mm or so gap around the lid to help make it breath better.
Carby just get jetted correctly for performance, makes a big difference, if it can breath as well.
Stock intake is fine, maybe a fiddle with port match to the intake ports and make sure that the gaskets are not sitting in the path at all.
What do you mean, you don't want to port the heads ? why not, no one can see it.
Stock headers, you mean stock exhaust manifolds.
I would get Better rod bolts for it for sure.
Stock exhaust like a HT GTS, yes and a bit bigger if you can.
What diff ratio 3.36 ? maybe a bit more stall, maybe a 186 converter will fit to give what you want.
Electronic ignition ? stock dizzy, with a Megaspark breakerless ignition, yes I would do something like that.
With cams just toss the stock old rubbish and get a new billet cam off a grind that will work for you want, I think you want something like what can not be detected as a modified cam on idle, with no lump and of stock performance with grunt right down low as a stock type but with more go mid and top, now what fuel do you want to run ? 91 or 98 ? that will come into it as well especially with the compression.
I think you would go for 98 octan if you don't do a lot of miles a year in it.
Compression is then up to what the cam says it needs, you could have a grind setup in regards to with no real regard as to fuel economy, you just have to talk with a cam doctor.
With boring out the engine I would get it torque plate honed and you may want a bit looser piston to wall speck to help it perform better.
Get the engine fully balanced it's worth it, not doing so on a grand mothers car would be ok.
I have seen stock exhaust manifolds perform well with free flowing exhaust, even with running big cams, the number one thing is that 308's hate exhaust restriction.
Heads a properly ported intake can be worth doing but it has to work within what the cams needs, the exhaust port is fine as is the std size valve, you can go for a L34 intake valve but the combustion chamber has to be modified the correct way as well for the big valve to work best.
Like Dr Terry said about HDT/Brock did, but knowing they did this crap stuff on a budget and ADR Laws.
When knowing all the tricks to get the old 308 racing car engines to perform and knowing that they had to comply with a lot of crap that cost them performance, if only they could of ported the heads the way they wanted too
But even with a small cam stock type of engine and all things just the correct way setup it can all add up to good gains in performance just where you want such to be, it's not all about maxim HP at 7000RPM 600HP type crap, you can make a stock type engine perform much better than the stock rubbish most drive about in and even within like you are saying your want, looking dead stock but potent awesome performing stock car that when you take one for a ride they will say get f ed ! that sure goes for a stock car man, not to mention you are sure happy with it and all.
Your exhaust manifold will not kill it, but the stock air cleaner will unless she is poking some of the filter out so as too let the bugger breath, all in all she can be made to still go real well, it's all about the fine tuning and attention to the details bit by bit working to help the results you want, not just some hair brain bunch of crap just tossed together and hope for the best crap that most do with too big a cam, ports done wrong, stupid carby, stupid great big intake manifold and end up with rubbish that sounds good to fools and goes well but nothing like it could of if they truly knew what they were doing.
