Camshaft selection

Depends on what your trying to get out of the motor. If you want just low end grunt I'd use cam 'B' as with the 112 degree lobe centers and the short duration you'll get a stump puller. If you want a broad power range with some top end horse power I'd use cam 'C'. It has the same 112 degree lobe centers for low end power combines with more duration and lift you'll get more flow for some mid to high end power. With the 4:10 gears I'd take cam 'C' if it were my choice.

Brian

driver with some towing(light to lower

hyd. lifter non roller cams specifically

...and with the 30% overdrive...?

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| > Anyone have any advise on what cam might suit my 'Burban best? Mostly a | driver with some towing(light to lower | > heavy weights) and some off roading(mostly trails or mild mud) All are | hyd. lifter non roller cams specifically | > designed for computer controlled engines... | >

| > Cam A--258/264 Advertised Duration(198/204 @ .050), .401/.423 lift, 104 LC | >

| > Cam B--250/258 Advertised Duration(192/196 @ .050), .392/.399 lift, 112 LC | >

| > Cam C--267/272 Advertised Duration(210/216 @ .050), .445/.445 lift, 112 LC | >

| > Cam D--252/252 Advertised Duration(201/206 @ .050), .406/.406 lift, 111 LC | >

| > Also, did they ever make a performance chip for late '80s TBI? | >

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Yes. My truck has a 3:42 gear with P265/75 R16 tires that are about 31-3/4" tall. In overdrive at 65 mph I'm running about 1500 RPM so I would guess you to be at around 2500 RPM. Sound right? That would allow you to run a cam that has mid to high end power with out effecting cruising. After all if your out to increase the power it's not in OD on the expressway that you want it. It's in lower gears with your foot in it. The cam 'C' listed below is very close to a 350cu in 350 hp cam of the seventies. They were designed for daily driving with an automatic transmission. The difference is that the early 350 that made 350 hp was 11:1 compression and had large valve heads and a big carb. But they still had low end power.

This is my opinion, you may want another cam.

Brian

I am right about 2000RPM at 60MPH in OD and I don't go into OD until about

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| > | > Anyone have any advise on what cam might suit my 'Burban best? Mostly | a | > | driver with some towing(light to lower | > | > heavy weights) and some off roading(mostly trails or mild mud) All are | > | hyd. lifter non roller cams specifically | > | > designed for computer controlled engines... | > | >

| > | > Cam A--258/264 Advertised Duration(198/204 @ .050), .401/.423 lift, | 104 LC | > | >

| > | > Cam B--250/258 Advertised Duration(192/196 @ .050), .392/.399 lift, | 112 LC | > | >

| > | > Cam C--267/272 Advertised Duration(210/216 @ .050), .445/.445 lift, | 112 LC | > | >

| > | > Cam D--252/252 Advertised Duration(201/206 @ .050), .406/.406 lift, | 111 LC | > | >

| > | > Also, did they ever make a performance chip for late '80s TBI? | > | >

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I would a cam with 114 degree lobe centers, the duration of cam D with the lift of cam C

-- Mad dog

driver with some towing(light to lower

hyd. lifter non roller cams specifically

WHAT??????? 65@1500????? Only works if you are very loose with your definition of "about" or you don't have a tach.

(Reminds me of "I did not have sex with that woman." or "It depends on what the definition of IS, is".)

That combination has to turn 1639.688051657567203780295306294 rpm's to be doing 65mph. Your rpm will vary slightly due to manufacturing tolerances and tire ware.

The big problem here is that there are no industry wide specifications on how to measure a cam. (Heck Chevrolet doesn't even measure all their different cams the same way). The figures given by one company may be for a cam that may be essentially different than a cam with the same or similar numbers from another company.

I would suggest buying directly from the cam manufacturer, and tell them what you want as far as performance. Let them decide which cam then make will best fit your needs. If you order from a parts warehouse, and ask them for their recommendation they will of course recommend one that they have in stock, which may not be the absolute best choice.

Most people buying an aftermarket cam end up with too much cam. Too much cam on a street driver makes driving in traffic a pain in the a$$.

This is usually a result of people just indiscriminately throwing any performance part in/on the motor without taking into consideration how they will interact with each other. Of course, this is usually done before they even think about the fuel map that is programmed into their ECM. End result=SHIT.

Rita

I did say about! There is no tolerance on about!

Brian