I have been running my 71 El Camino with a Richmond 4.88 GM 12 bolt posi with a TCI TH350 Street Fighter with those said combos listed.

Runs and launches great. Its just that I have been running out of breath and gears(?) by almost to the finish line. I love to keep it with the same gear as I have made high 12s easily with a little struggle by the finish line at 6,500rpm.

The tires are M&H Race Master DOT 27.5/15.

Now, please give me an opinion as one of my friend sold me his M/T 29.5/15/10.5W. I only need to trim the lips to clear this tires with my 5.5 back spaced Centerline 15x10in rims on that listed M&H tires.

Do you guys think this will help with my top end? At least little more?

Thanx in advance. Try it out tomorrow, on my day off.

Oh yeah. That will help. You should see a noticabe difference.

you could always change to a larger camshaft to make use of the deep gears. Looks like you`ve got enough compression. If you want to stick with a hyd cam then I would recomend a Isky 304 mega or if you want to go solid then a Isky Z70. you should change the intake too,maybe a victor jr. either cam should have you shifting around 7000-7500rpms and would probably like the deep gears.

The 2 inch diameter change should give you another 7 mph at the same rpm or reduce your rpm by about 400 at the same mph.

Use this link for a nice selection of race calculators:

http://www.tciauto.com/tech_info/calculators.htm

I would look to changing the manifold too, the one you have is not very good.

Thanks!

I did some road testing. I was not able to full run (quarter mile). But yes, it does hold more and felt that significant change on gear ratios. It felt like as what the calculator said, like it reduced to 4.55 or something. Felt better.

Launch was awesome (on the street...).

Also, for those who wonder if these tires fit in my stock rear non tubbed, just to share what I did that by limiting the spring travel with those rubber boosters (three in a row), then I lipped and banged little on the inner wall above the lip, I was able to tight but fit the M/T 29.5/10.5W/15 slicks with a Center Lines 15-10 with a 5.5 back spacing rims. Sure looks meaty and mean too. But of all, awesome traction.

if i remember correctly,that intake manifold is better suited to smaller,lighter cars.i think even the original torker would be better than the torkerII for your ride.

Thanks for the advise. I am going to get Victor JR. I have heard about the torker II.. Its just that I had the torkerII around when I built the motor in my garage, I ended up with it.